Crack achievement investigators Xbox360Achievements.org are back in action, and they've sleuthed out the 50 Achievement/1000 Gamerscore set for Batman: Arkham City.
Included are two achievements speaking to a New Game Plus mode, which will allow a second playthrough with your fully upgraded Batman. Pore over the others, and then see Kirk's impressions from PAX and mine from Comic-Con to see if any of them concern details we haven't seen. (Hint: There are, and not just in the obvious story-chapter achievements.)
Batman: Arkham City Achievements [Xbox360Achievements.org]