Microsoft was showing off a future version of their Microsoft TV product at CES. Here in the US, the closest thing we have to this at the moment is Microsoft TV - Foundation Edition which Comcast has deployed in some cities. This version has been covered elsewhere quite a bit, and strikes me as a pretty basic system. Basic PVR, basic program guide, and so on.
The version on display at the show was the new MSTV - IPTV Edition designed to allow folks like SBC and BellSouth to enter the television market over their IP networks. The idea is to deliver HD-quality streams at 3-6Mbps into the home in both unicast (video on demand) and multicast variants. The system has a much sexier user interface than its Foundation Edition cousin. It looks almost exactly like the Media Center UI (alpha-channel transparency effects and all). I was pretty impressed. The system apparently puts most of the smarts in the network and is designed to work within a very small footprint on the client device.
An early version of Microsoft TV - IPTV Edition has already been deployed in pilots in Canada and Europe. SBC and BellSouth will start trials in the US later this year.