Of course it will be available in most countries. A quick search has the UK covered anyways by a few independants.
http://www.superetrader.co.uk/nokia-...e-p-12773.html
More will follow. The only reason the N9 WP might not launch with some carriers is Skype. But as seen with the Indian versian of N900 they can disable it by firmware region, which can be got around anyway.

By the way just come across this webpage, has a lot of information on N9.
http://www.n9fanclub.com/