As noted by TechCrunch that the official Facebook app for iPad will be available soon in the App Store for iPad 2 and iPad 1.
They found Facebook app hidden on iPhone app. The good news is that you can now install hidden Facebook app on iPad 2, 1 before Facebook release it officially. Below you will find a video showing you how to install Facebook on iPad 2, 1. Enjoy
The app also makes great use of the pop-overs (overlay menus) found in other iPad apps. When you flip the iPad horizontally, the list of your online friends appears and you can chat with them as you do other things on Facebook. The photo-viewer aspect looks great — similar to the iPad’s own native Photos app. Places exists with a nice big map to show you all your friends around you. Etc.