Batman: Arkham City PC patch fixes save corruption

Ever since the PC edition of Batman: Arkham City launched in November 2011, an unlucky portion of players have been finding their save files mysteriously corrupted and their progress lost. Four months later, Rocksteady Studios has finally released a patch addressing the problem, which even salvages the saves for some--but not all.
"Sadly we cannot guarantee that all lost saves will return but did all we could to bring them back," Rocksteady community manager Sarah Wellock explained on the forums.
The patch is already out on Steam, and is due to hit Origin and Games for Windows Live soon. Here's the hit-list of the problems it's targeting:

Occurences of Save File Corruption

Achievement re-locking issues

Crossfire/SLI Issues

Graphical flickering

FPS improvements when running crossfire

Instances of 32 bit memory problems

Improvements to performance in cut scenes and death taunts

Error messages removed when patching the game and improved patching process