What I would really, really like:
1) To be able to choose to (doesn't have to be default) delete shared Recorded TV content from other Media Centers.
It just doesn't make any sense not to since Extenders can do it. And I know MC can easily do it because if I run a WTV file from a network share with MC it lets me delete it.
It is frustrating to have to switch to Windows Explorer to delete shows from another PC. It is VERY frustrating because you can't do this with a standard MC remote control. It is annoying when I am down in my basement home theater, but it is infuriating in the kitchen where I keep the keyboard safely hidden away in a drawer.
2) To be able to schedule programs to record on other shared Media Centers.
Not fancy remote internet stuff, just let me tell my primary MC with multiple tuners and 6TB of storage to record a show later, from MC on my awesome little ASRock net-top in the kitchen. Again, my Xboxes can do this, why shouldn't my Windows 7 Pro PC do it?