Seeing HTC leak a shot of a product through a confidential FCC filing is about as rare as a confirmed yeti sighting, so you can imagine our excitement with this fresh meat that just landed in the Fed's files today. What is it, exactly? Well, it's a smartphone running 3G on WCDMA Band IV, which -- for those who don't have their bands memorized -- is the AWS spectrum that T-Mobile uses. In other words, we'd bet our bottom dollar that this is the rumored Android-equipped myTouch Slide that we're looking at here -- and with a Spring launch window