Several Steam users posted what look to be captured screenshots of the portal's stats page, but with a whole bunch of unexpected names on there.
Other standout games on the list include beat-em-up Battleblock Theater and multiplayer action game Happy Wars, both currently only on Xbox Live Arcade. Half-Minute Hero sequel Hero 30 Second is only out in Japan, but Half-Minute Hero Two is also on the list.
While Arkham Origins came to home consoles and PC last year, Warner Bros. released 2.5D game Arkham Origins Blackgate alongside it on 3DS and Vita. There's been no word of an HD port of the portable game, and when approached about Blackgate HD's name being on this list, a Warner. Bros representative told Joystiq, "We have no comment on this."
The stats page is back to normal now so we've been unable to verify the screens, and even if they're accurate they don't provide any confirmation the games will be released. That said, each one of the games we've mentioned certainly sounds plausible, so we'd say this is a space worth a watch.