While the game won't be released until tomorrow, you can now try a demo
of ARMA II
. The demo is available through Steam and should give you a good taste on what its all about. Those looking for a more realistic feel to the FPS genre so it might be a little tough to get into. I've also heard of some bugs that's keeping the game down since it's release in Europe. Let's hope they fix it up soon for both them and for those of us in the US.