This latest demo for the multiplayer portion of Crysis 2 will give you access to two maps (Skyline and Pier 17) and two of the game modes, Team Instant Action and Crash Site, as well as two maps,
The full version of Crysis 2’s multiplayer component will include “six intense, action-fueled gameplay modes: Instant Action, Team Instant Action, Crash Site, Capture the Relay, Extraction and Assault, set across 12 maps in Crytek’s visually stunning recreation of the Big Apple.”
Currently downloading it now.
Strangely it wasn't showing up on the market on my console but it's there if you go to xbox.com.