May be old news to some, but I just found out about it. Apparently it will be completely free, no micro-transactions, and co-developed by Epic and the Unreal player community.
It is nice to see a well known developer do a multi-player shooter that is not military themed. Brown and bloom got old back in 2008. If they can pull of what valve has done with TF2's community sourced items and maps it will be a fun game. I will be following this.
Epic will be in charge of the the core game with the community fleshing out the game with content. There will be some micro-transactions like there are in TF2 with the profits being split between the maker and Epic.
I am liking the sound of this more and more. Epic gets a way to show off their new engine to everyone, they get people interested in using their toolset, and gamers get a new free Arena shooter.