What with the 1000 DVD changer (mind you, I'd rather rip them all to a terrabyte server...) and the fact that DirecTV seems like it's going to be dumping TiVo like a lead ballon, I really want to switch to Media Center. Not least the fact that I want all the TVs in my house to have access to the same media repository - the same recorded TV shows and the same audio library, plus all the home videos.
My only blocking point is HDTV. I need HBO, Showtime and Discovery in a recordable HD fashion. DirecTV gives that to me now via my HDTiVo.