This was what the FCC shows:
According to the U.S. Federal Communications Commission's online database, a "magic track-pad" or a "magic slate" was approved for production. The details on this track-pad are few, but what we do know is that is works with Bluetooth, WiFi and WWAN networks. It also only appears to be a accessory, since it lacks a screen, as seen is the photos bellow. The device is rumored to support multi touch gestures, similar to the ones in recent Macbooks and iMacs as well as every feature on the current mighty mouse.. Also, some claim that it will even have handwriting support, which seems fairly likely. Apple has done a lot to keep this project under wraps, more so than most of their other accessories, such as iPhone 4 cases. Therefore, we can speculate that it will be a major accessory to Macs, and possibly iPads and iPhones.