I asked Hakan about this and he replied:
Microsoft does realize the importance of providing great content to consumers, and we currently have over 250 online services to consumers on a world wide basis. In UK, we currently have the following services available to users for Windows Media Center and Extenders:
FunspotUK
BBC Newsplayer
Contact Music
ITN
TVOnTimeUK
Sportal
MTV Overdrive UK
Live365 UK
Coolroom
TVOnTime.SV
My Station.SV
Funspot.sv
We appreciate your suggestion to add Virgin and Sky to the offerings and will definitely consider this for future versions of Windows Media Center.