The release version, it features:

A new zombie
A M4 Carbine/Bow
M4 Ammo/Arrow
A Better Steak
AHiPhone/Book
Stealth Vest/Leather Armor
Space Suit/Chain Armor
US Army Uniform/Iron Armor
HAZMAT Suit/Gold Armor
Riot Suit/Diamond Armor
Iron Knife/Iron Sword
Diamond Knife/Diamond Sword
Carbon Knife/Stone Sword
Baseball Bat/Wood Sword
Chainsaw/Diamond Axe
Better Iron Pickaxe,Iron Shovel,Stone Shovel,Fishing Rod,Grass,Dirt
New Jukebox and Note Block
Floppy Disc/Music Disc
TV/Pumpkin
Modern Furnace and Crafting Table
Better Paintings
Modern GUI
Better Mushroom Soup
Solar Panel/Daylight Sensor
Better Wooden and Iron Door
Better Trapdoor
Modern chests
Better Rain
Little modified Apple
Bottle/Brewing Stand
Whiskey Bottle/Bottle
Gas Can/Lava,Water and empty Bucket
Dollar/Green Dye Powder
Cent/Gold Nugget
Better Diamond, Iron Ingot and Gold Ingot
Chocolate Cake
Modern Bed
Better Emerald
Lighter/Flint and Steel
Ban Hammer/Gold Hoe
Better Magma Cream
Better Emerald,Gold,Iron Blocks
Better Ender Chest
Better Grass and Snowed Grass
Modern Glowstone and Redstone Lamp
Blue Cable/Redstone
Better Redstone and Normal Torches
Better Lever
Better Tripwire Cable
Better Itemframe
REALISTIC Acacia Wood
Better Wood
Modified some Stained Clay
Modern Pistons
Better Glass
Better TNT

The second version of the pack:
New Bow/M16A4
New Cobblestone
New Sand
New Iron Door
New Daylight sensor
New Painting
New Boat
New Mobspawner
New Diamond Sword/Laser Sword