Just noticed this on the My Crysis website:

Experience All of Crysis Wars Absolutely Free October 10th – 12th

http://www.mycrysis.com/newsdetails.php?news=38014

I'm just trying to get through the single player before I start getting into wars, but I'll definitely try and join you guys for a game sometime.  Just wanted to post this in case anyone has been on the fence about getting it to try it out.  Have fun!