Originally the fevered dream of Microsoft executives circa CES 2007, the Xbox 360 IPTV box is rapidly becoming a reality, first sneaking into Canadian carrier Telus' Optik TV outlay and now reportedly in development at AT&T. Now, we wouldn't have blamed you for doubting Microsoft when it briefly mentioned U-Verse subscribers would get Mediaroom functionality in your game console later this year, but it's looking more likely now: a tipster just forwarded some legit-looking screenshots of Xbox prompts in AT&T U-Verse's technical support database. Our source cl