Some answers
"Will this service be world wide or do the distributors/networks still don't get it? World wide service would be nice :D"
I would imagine Sky only have UK broadcast rights for most of their shows.
"If you watch Sky, streamed to your Xbox, and Iplayer on your PC (and no satellite dish, or TV aerial etc) and live in the UK, do you need to still pay a TV licence?"
If it's streamed live (as in, if you're watching a feed that's also being broadcast over the air) then yes. If you're just using the on-demand service then no.
"Is the multiroom subscription required for everything or just streaming live channels, as it already is for the PC version of Sky Player?"
I can't imagine it'd be different to the exisiting Sky Player service.
"We are now in the world of HD so it's rather pathetic providing VHS quality on demand services and expecting people to pay for it. The best streamed quality I've seen is from the BBC iPlayer, but even that looks terrible full screen on a 40" TV."
No idea what quality the Sky service will use, but the upcoming update will include the 1080p live streaming from Zune Marketplace, so it's possible that the Sky service could stream in HD.
"and pay for multiroom? when i don't get the same quality or amount of channels over skyplayer that i would do normally? wtf? yeah sure, that bird'll fly. if it was a free service like PC skyplayer, then cool. but it's not. so bye bye."
The PC service requires multiroom for live streaming (as opposed to VOD). However, I think that Sky Player on Xbox will require an Xbox Live Gold subscription.