MCI Craft currently contains 4 parts: Core, Farming, Machines and Redstone. Both Machines, Farming and Redstone are optional. Below is a list of some blocks/items that are added to Minecraft.

Core

Nuclear Bomb
Nuclear Bombs are 10x more powerful than TNT.
Mineshaft Mole
The Mole is a machine that digs Mineshafts and places supports (Fences and Planks) as it goes. It requires Coal as its fuel source and Wood for the supports. If it is supplied with Torches and Rails it will place them but they are not required. When turned on it will mine a distance of 60 blocks from its source before turning its self off. How the Mole is placed will determine its orientation. It can mine a Mineshaft in all directions (Up, Down, North, South, East and West).
Mass Accelerator
The Mass Accelerator reduces the mass of any object in its field (For the duration it is in the field) and accelerates it in a specific direction. It is useful as fast transport, TNT Cannons and making elevators. As it internally contains Redstone Torches it does not need any external power source.
Slowdown Block
Slowdown Blocks slow anything that moves though it. They are good at preventing falling damage.
Uranium Ore
Uranium Ore is used as fuel in PHW Reactors.
Plutonium
Plutonium is a by-product of using a PHW Reactor. It can be used to create Nuclear Bombs.

Machines
(Requires: Buildcraft or Thermal Expansion)

Solar Panel
Solar Panels generate power based on the light level. It is best to hook them upto a Power Storage so you can store power during the day when you are not using any.
Electronic Furnace
Electronic Furnace's are like the normal Furnace except that they require power to operate and they can smelt 3 items/blocks at the same time. It can store upto 1,000MJ.
Power Storage
A Power Storage can store upto 10,000MJ. By applying a redstone signal you can stop the Power Storage from supplying power to connected Pipes/Machines.
PHW Reactor
PHW Reactors (Pressurized Heavy Water Reactor) generate 25MJ per Tick (500MJ per second). They require Uranium Ore as their fuel. Each Uranium Ore lasts for 4 Minecraft Days giving a total of 2,400,000MJ. To operate they require a constant supply of Water and Heavy Water as well as an active redstone signal.
Fluid Separator
The Fluid Separator allows fluids to flow into it from any side but only allows Oil, Water and Lava to be drained from specific sides. It can be placed on top of Pumps to allow fluids to be filtered so your operations won't get clogged up with the wrong type of fluid. Because of the pressure inside of the Fluid Separator, Wooden Fluid Pipes and Emerald Fluid Pipes do not need any external power to extract fluid from the Fluid Separator.
Water to Heavy Water Converter
Water to Heavy Water Converter's use power to turn normal Water into Heavy Water which is then used in PHW Reactors.
Bucket (Heavy Water)
A Bucket containing Heavy Water.
Universal Transmogrifier
The Universal Transmogrifier is designed to merge all OreDictionary items that have the same OreDictionary name into a single type. When a Duct/Pipe places an item into the Transmogrifier it is instantly converted allowing another Duct/Pipe to extract the item.

Redstone

Redstone Circuit Board
Redstone Circuit Boards are used in the crafting of Redstone Gates and circuits.
Redstone TileEntity Chip
Redstone TileEntity Chips are used in the construction of Advanced Redstone Circuits.
Redstone Crossover
Redstone Crossovers allow a redstone signal to pass through it from 2 directions at the same time without the 2 signals interfearing with each other. Signals flow between North and South as well as East and West.
Redstone AND Gate
An AND Gates output(Back) is on if both of its inputs(Left & Right) are on.
Redstone NAND Gate
A NAND Gates output(Back) is off if both of its inputs(Left & Right) are on.
Redstone OR Gate
An OR Gates output(Back) is on if one or more of its inputs(Left & Right) are on.
Redstone NOR Gate
A NOR Gates output(Back) is on if both of its inputs(Left & Right) are off.
Redstone XOR Gate
An XOR Gates output(Back) is on if only one of its inputs(Left & Right) are on.
Redstone XNOR Gate
An XNOR Gates output(Back) is off if only one of its inputs(Left & Right) are on.
Redstone NOT Gate
A NOT Gates output(Back) is on if its input(Front) is off.
Redstone Toggle Latch (1 Output)
A Redstone Toggle Latch's Output (Back) is switched between an on and off state when the Input (Front) is turned on. The input needs to be off before it can toggle another change in the output.
Redstone Toggle Latch (2 Output)
A Redstone Toggle Latch (2 Output)'s Output (Back and Right) is switched between an on and off state when the Input (Front) is turned on. When one of the outputs is on the other is off. The input needs to be off before it can toggle another change in the output.
Redstone Randomizer
A Redstone Randomizer's output (Back) is randomly turned on for a random duration if its input (Front) is on.
Redstone Signal Extender
A Signal Extender is designed to lengthen a redstone signals duration. It has 4 settings which can be changed by right clicking on the Signal Extender. The settings are 1, 2, 4 and 8 Tick durations. There are 20 Ticks per second.
Redstone Signal to Pulse
A Redstone Signal to Pulse turns a redstone signal into a single 1 Tick long pulse. This is useful if you want to turn on something for a specific duration (When used in combination with Redstone Signal Extenders). It will only send another pulse if the input(Front) signal is turned off and on again.
Redstone RS Latch (1 Output)
A Redstone RS Latch's output(Back) is toggled on and off by a redstone signal to one of the two inputs(Left and Right). When the Right input is powered it will toggle the output(Back) to be off. When the Left input is powered it will toggle the output(Back) to be on.
Redstone RS Latch (2 Output)
A Redstone RS Latch's output(Back and Front) is toggled on and off by a redstone signal to one of the two inputs(Left and Right). When one output is on the other is off. When the Right input is powered it will toggle the Back output to be off and the Front output to be on. When the Left input is powered it will toggle the Back output to be on and the Front output to be off.
Zero Delay Redstone Repeater
A Zero Delay Redstone Repeater is like a normal Redstone Repeater in that it repeats any redstone signal sent to it but unlike Redstone Repeaters it has no delay.
Redstone Numeric LED Display
The Redstone Numeric LED Display displays numbers based on the length of a redstone current supplied to it. If a redstone current is supplied for 1 server tick it will display the number 1, 2 server ticks for 2 and so on. For displaying a 0, a signal that lasts 10 server ticks is required.
Redstone T Junction
A Redstone T Junction is like Redstone Dust except that it only connects on 3 sides and outputs a current at a strength of 15.
Redstone L Junction
A Redstone L Junction is like Redstone Dust except that it only connects on 2 sides and outputs a current at a strength of 15.
Redstone Inventory Counter
The Redstone Inventory Counter sends 3 output signals based on the total number of items in a Chest which is located at the Redstone Inventory Counter's front. The signals are designed for use with Redstone Numeric LED Displays. Its output is limited to a maximum value of 999.
Redstone Input Merger
The Redstone Input Merger is an extention to certain Redstone Circuits which require more inputs than can be achieved alone. The Input Merger takes two seperate inputs and merges them into a single input for the Redstone Circuit it is extending.
Redstone Output Splitter
The Redstone Output Splitter is an extention to certain Redstone Circuits which require more oututs than can be achieved alone. The Output Splitter takes a single output from the Redstone Circuit it is extending and splits it into two seperate signals.
Redstone Half Adder
The Redstone Half Adder adds the two inputs (A and B) and outputs the sum (S) and carry (C). The carry is meant to goto a Redstone Full Adder.
Redstone Full Adder
The Redstone Full Adder adds the two inputs (A and B), accounting for the Input Carry (Blue C) and outputing the Sum (Red A) and Carry (Red C) to a Redstone Output Splitter. The output carry is meant to goto another Redstone Full Adder as its input carry.
Redstone Half Subtractor
The Redstone Half Subtractor subtracts the two inputs (A and B)and outputing the Difference (D) and Borrow (C). The output borrow is meant to a Redstone Full Subtractor as its input borrow.
Redstone Full Subtractor
The Redstone Full Subtractor subtracts the two inputs (A and B), accounting for the Input Borrow (Blue C) and outputing the Difference (Red A) and Borrow (Red B) to a Redstone Output Splitter connected to the back (Yellow). The output borrow is meant to goto another Redstone Full Subtractor as its input borrow.
Redstone Binary to Pulse
Redstone Binary to Pulse turns 4 input signals (The binary values 1, 2, 4 and 8) into an output pulse with the appropriate length for a Redstone Numeric LED Display. A Redstone Input Merger needs to be connected to the front of the binary splitter (Purple side).
Redstone Column
Redstone Columns allow Zero Delay redstone signals to be sent upwards/downwards. They only pass a redstone signal to another Redstone Column or a Redstone Column Circuit. A Redstone Column Circuit is required for the input redstone signal. When Right Clicked while holding no items/blocks the Redstone Column changes between the two modes. By default it won't connect to blocks at its sides and won't pass on the redstone signal it gets to them, but when switched to its alternate mode it will send a redstone signal to all 4 of its sides.

The Alternative mode allows you to make things like a Zero Delay Piston door where all the Pistons activate at the same time, no matter their height.
Redstone Column Circuit
The Redstone Column Circuit is like a Redstone Column but which has no alternative mode and a singal input/output on one of its sides. It sends a redstone signal above and below it to other Redstone Column Circuits as well as Redstone Columns. It has a 1 Tick delay.
Redstone Binary Decoder
A Binary Decoder converts binary input (Through Redstone 2 Bit Inputs connected to it) into a decimal number which is passed to Redstone Numeric LED Displays that are next to it. The binary input goes in a anti-clockwise direction, the first being 1 and doubling for each additional input.
Redstone 2 Bit Input
The Redstone 2 Bit Input provides binary input for the Binary Decoder. The value each input represents are based on how many 2 Bit Inputs are connected to the Binary Decoder. The values start at 1 and double for each additional input going in a anti-clockwise direction.