See, back in August we posted a list of "unofficial" Fable 2 achievements that leaked their way online. Now these new achievements, they're official with official artwork AND we noticed a few differences. Don't worry though, from what we can tell no actual achievements have been added or removed since the August leak. Instead, a few descriptions have changed including our favorite of the bunch, "The Swingers", which now reads "take part in a debauched bedroom party with several participants." Nice!
The other major difference between the unofficial and official Fable 2 achievements is the added ability to unlock some achievements not by doing the action, but rather seeing someone else perform the act. Meaning that Gamerscore can be earned simply by watching a friend ("Hero") complete the task. Think of it as an achievement tag team effort.