The cat is out of the bag concerning Assassin's Creed III's setting and main character, but there is a lot more still unknown about the game. One potential inclusion for AC3 is co-op play, which was spotted earlier on the Xbox Marketplace but has since been taken down. The co-op mode could be anything, from an aspect of single player to a separate mode like Mass Effect 3's co-op. Microsoft was not the only company to slip up, as GameStop's product description contains a hint about co-op being included. While it does not say it directly, the ability to team up "with your comrades at your side" is a pretty strong indicator for co-op. Whatever the case may be, we will just have to wait to find out.
Assassin's Creed III is due out on October 30th for the PC, PS3, and 360.