Here's the things I think are most important:
- Some of our favorite old maps are returning i.e. Dust, Dust2, Inferno, Nuke, etc.
- A greater variation of weaponry with differentiated effects depending on the type of weapon used.
- This is cool, "Decoy Grenades" can be thrown to emit gun sounds and the like in order to confuse enemies.
There's more information in the full story which you can read HERE
Still no official release date for CS:GO other than early 2012.