There’s a tool to check what games are registered on Steam. Well, it’s mostly reliable and has leaked many games coming to the service.
Furthermore, it looks like there are plenty of new games that could be heading to Steam. People normally use this tool to peek into the Steam database.
Some of them are games we already know like La-Mulana and Resident Evil: Revelations, however, Halo 3 has also been discovered in the database which could mean, Microsoft will start releasing older Xbox 360 games published by Microsoft Game Studios on PC, or Valve is adding support for Steam Community hubs for non-Steam games.
Here’s the listing for Halo 3 (via GAF). You can find the complete list of all the games that have been found so far below, and plenty of them are already confirmed to be heading to Steam. Games like Fez are obvious because it was confirmed to be going multiplatform.
Has something gone wrong or Halo 3 is indeed coming to the PC? Well, we know for a fact that earlier Microsoft was planning to monetize Steam, so time will tell, but for now there’s hope considering this Steam database tool has been mostly accurate.