Update: It looks like Halo isn't coming after all.
"We currently do not have plans to release any 'Halo' titles on Steam," said a Microsoft spokesperson in response to our query.
Original story: A giant list of games on the Steam database was leaked via the Steam Apps Database, a site dedicated to navigating the labyrinthine maze of knowledge and patent placement that is the Steam registry data.
The list contained such notable titles as Halos 1-3, Fez, The Witness, Quantum Conundrum 2, Lococycle, Owlboy, Gunpoint and Dyad.
No one knows how the Steam database works exactly, so it's unclear if these games are actually coming to Steam or if Valve will be adding community hubs for non-Steam games. Or maybe they're just placeholder registries just in case the publisher and Valve decide to bring them to the popular portal later.
While most developers aren't willing to disclose what their game's status is regarding Steam, Dyad creator Shawn McGrath has confirmed to Joystiq that his psychedelic PSN shooter would be making the leap. "This was a rather interesting thing that happened," McGrath said. "I didn't plan on announcing Dyad on Steam yet, but what can I do now?"
McGrath noted that he'd been in talks with Valve regarding a Steam port since March, but nothing was certain until October. He's shooting to have it out by March, "but who knows when it'll actually come out?" he added. McGrath is hoping for a simultaneous PC, Mac and Linux launch, but may have to settle for launching the PC version ahead of the other two.
Elsewhere, Fez creator Phil Fish simply responded to my query with a simple, "no comment for now!" response, but given that Fish has said he'd like to make Fez multiplatform, the Steam version seems very likely.
We're still ringing some proverbial doorbells trying to get the skinny on what games are definitely coming to Steam rather than just probably coming to Steam. For the full list of games originally outed on the database go here.