I had long wanted to play Batman: Arkham Asylum and Arkham Origins on PC for the prettier graphics and improved physics, but the Games for Windows Live requirement pushed me into playing both titles on console. That's no longer an issue. Similar to BioShock 2, the pair has moved away from the service as Microsoft winds it down in the coming months.
If you own either title on Steam, just wait for the update to do its thing -- Arkham City now has a Mac version included. Otherwise, you can redeem your retail copy through the platform and, even if it's just the vanilla game without DLC, you'll end up with the upgraded game of the year edition. Unfortunately, this will result in having to start a new save file. Think of the Riddler trophies.
To accompany this news, the games are on sale. Arkham City and Arkham Asylum are down to $7.50 and $5, respectively, for the weekend. These are the game of the year editions, too!