Earl over at DBSTalk has posted what appear to be official brochure scans for DirecTV's long anticipated, at least 2 years long, USB HDPC-20 PC Tuner. The dual tuner receiver will allow you to use your PC as a DVR while watching DirecTV programming, hopefully in HD although the brochure makes no mention of it. I'm guessing yes by the model number but we'll have to wait for more info to leak/surface from DirecTV. It looks like only support for Vista Media Center PC's, no word on Mac support just yet.

