RoadRunner, glad to hear you like Media Center. Was it the Vista version?
I started at MS in early September but ran a large study on Media Center covering success rates, time to complete tasks, and where errors are made in the latest version. I'm pushing some changes up to the managers and some UI changes will most likely be seen in the next release, though I'm not at liberty to say if that's in a service pack or Windows 7.
With all the criticism Microsoft gets (and believe me, I certainly give it too!), it's nice to know they value user experience. Involving users in design makes software that much better. :)