FireFall is an upcoming FPS/TPS Sci Fi MMORPG from Red5 Studios. Like League of Legends and Battlefield Heroes, it will be completely free to play (with a few microtransations for non-game changing things)
FireFall is an open world shooter RPG with team based elements. It has a Borderland's-esque cartoony graphics style, and like Borderlands, has you go out with friends to fight off all kinds of alien nasties as you complete missions and find resources. The game has modular armor and weapons, allowing you to upgrade them with custom abilities and firemodes as you progress through the game. Your character can also find things like backpacks that they can attach to their armor to give them abilities such as an electric shockwave, a healing pulse, or even wings to glide with.
FireFall is set to release before the end of 2011, but will have a public beta open soon.