Yeah Microsoft isn't developing for WebTV/MSNTV anymore.  They just have their servers running and customer support open.  That's about it.  The UltimateTV and Dishplayer are no longer supported- can't activiate them anymore through DirectTV or Dish.  I think UltimateTV will technically work but it wont do HD.

Most of the original engineers went on to start Xbox, Microsoft's IPTV platform, Android (before it was bought by Google), Onlive, Moxi Digital (before it was bought by ARRIS).  So the people behind WebTV have definitely moved on...