Crytek is releasing a free to play FPS game. It has both "pve" and "pvp," which is really interesting in my opinion! They're trying to make it so it can run on any pc, no matter how low end or high end it may be. They're goal is to make it a next gen FPS and have more team play and daily content updates to the PVE part of the game (think that may be a bit much eventually, every day!) It is supposedly being released sometime this year, but there isn't any set date.
You can sign up for the closed beta on the main site
here, as well as the email list, and 'reserve' your nickname.
Check out the website for more information, trailers, and screenshots!
http://www.warface.com/