This brand new v1.11 demo showcases both the basic Shock Force game as well as the Marines Module, sold separately from the basic game
Battlefront.com has released an updated demo for Combat Mission: Shock Force, allowing you to try out their strategy game that depicts a hypothetical near future conflict between NATO and Syrian forces in Syria. This demo includes three scenarios which can be played as either US or Syrian. It also offers a fourth scenario, "Demo Training", which was designed to only be played from the US perspective. All multiplayer modes are active (TCP-IP, PBEM, Hotseat) and you can access the full Game Editor, but the save function is disabled.
Update: the Paradox and GamersGate versions of the latest patch for the game are now available.