Now Microsoft has shut down Games for Windows Live, what happens to the one use anyone had for it--buying the Minerva's Den DLC for BioShock 2? Thankfully 2K has switched over to Steamworks, updating the game and very nicely giving the add-on free to everyone who already owned the base game. For goodness' sake, play it if you haven't already.
Multiplayer now uses Steamworks, and all MP DLC packs have been set free for everyone. People who buy BioShock 2 from now onwards via Steam will need to buy Minerva's Den separately, but if you already had it, you now have Minerva's Den too. Presumably setting up a way to verify whether people had purchased it on the GFWL Marketplace was not worth the effort.
If you have a boxed copy or snag BioShock 2 from another digital distributor, you can activate that key on Steam to add the game plus Minerva's Den and the MP DLC to your library, 2K explains.
Saves, achievements, and multiplayer progress from the GFWL version won't carry over, though.
Plus the game's been jazzed up by Digital Extremes for Steam, now boasting official controller support, Steam achievements, and Big Picture mode support. The SecuROM DRM is gone too.