Id say Japan will jump on Vista and it will be as natural as babe to it's mothers breast ...
They seem to welcome 'new' technology', in whatever form and are keen to get their hands on it.
I would hazard 60-70% penetration by year end.
Singapore -- I havent heard anything much here, no fuss or big advertising push (Small population -- less than 4.5 million so hardly worth the effort) And while some will upgrade I doubt it will matter much.
I did have a play with it today and it is nice but for me XP works fine and I have no plans to upgrade.
China -- Good penetration, I would imagine it has been cracked, whacked and packed a while ago and tweaked to get updates -- 50% penetration by year end.
Europe -- No idea, a long time since I was back there.
And, purely in the interests of ..... whatever -- below is a snapshot of what is freely available for download from a well known bit torrent ...