Microsoft's early efforts in TV are documented here:
http://research.microsoft.com/~mbj/papers/mitv/tr-97-18.html

I worked many years in the WebTV/MSTV group, so it's strange that I didn't know many of the people written up in this paper. Of course a few names are familiar, but the overall lesson is that Microsoft, as a big company, can do big things, many of which never see the light of day. There were two main streams of people working on TV at Microsoft: the Tiger people and the WebTV people. The WebTV people eventually overtook the entire effort, as the center of the project moved to Silicon Valley. All the great work done on Tiger eventually simply faded into the rest of Microsoft, in the form of people who no longer work on TV at all.