"Yeah, the Halo 3 thing is almost certainly a community hub, there's no way Microsoft would port a 6 year old game to PC - especially seeing as Bungie are no longer working on Halo, and 343 have Xbox exclusivity. Will still be interesting though if Steam starts supporting hubs for non-Steam and non-PC games - although Raptr already does that. Still, I think Steam, what with Valve being a profitable company unlike Raptr being free will do a much better job of it.
Apart from that, glad to see Fez and Duke Nukem 3D coming to Steam! Also, Halo 1/2 are a possibility - we've seen Fable appear on Steam and that's a Microsoft GFWL game, so here's hoping for 1/2. Perhaps even Steam Halo 2 servers considering the 2 servers are now dead? That'd be awesome. Sorry about the lengthy comment!"