This whole policy stinks to highheaven and they only get away with it because they can! They even have the nerve to call it a worldwide warranty!
I bought my D70 in the UK (I live here), broke down whilst on holiday in Canada, Nikon Canada (very close to Toronto, where I was), refused to even look at it without charge, as it was not a North american purchase.
'Worldwide warranty' ...my foot...this is corporates getting away with diffrential pricing in different countries only because they can. I don't want to rant, but this really is going too far.
I still buy Nikon, because I have for 20+ years and I like the kit + the competitor (Canon) doers the same, but that doesn't make me like it one bit.
If any reasonable DSLR manufacturer came up with a truly worldwide warranty, I would switch systems in a blink.
+ It might be worth (especially for travelling pros - I'm a hobbyist), looking at wheter this is really legal, afterall (irrespective of the fine print) you shouldn't be able to call something a world wide warranty if it clearly isn't!