It has already been officially released but it was after the IOS5 launch.According to what I read it was launched at Apple’siPhone 5 launch event on Oct. 4. The Facebook iPad app, which leaked earlier this year, has been in limbo at Facebook for the past few months.
They also stated this. "The problem, according to two sources familiar with the situation, has been a combination of timing and a strained relationship with Apple. It’s no secret that the two companies have been at odds over various issues during the past two years. For example, the social network pulled the plug on Facebook Connect in Ping because Apple didn’t give Facebook any warning about the feature, which would have eaten a great deal of bandwidth on Facebook’s side." -http://mashable.com/2011/09/26/facebook-ipad-app-iphone-app-exclusive/
I've found that the latest facebook app is really buggy. I launch the app and it stays at the blue 'facebook' screen for about 40 seconds. The UI is gorgeous, but functionality is more important, IMO.I get it last night, and it works on my ipad, so amazing