Wow, economy is crashing in all around them and Nikon USA (who has been badly impacted) wants to be picky about where a lens was originally intended to be sold, good luck with that. I find it hard to believe that they are currently turning away paying customers because an otherwise official Nikon lens was not originally intended for the U.S. market. Are we to believe that Nikon is making the same lens differently depending on the country they intend it to be sold in?
If Nikon Canada did that I would switch to a different camera system -what a myopic customer service policy. Here it does not appear to be an issue, I recently had a U.S. version of a 70-200 (mkI) serviced, no questions asked. Further, I know several people here who have bought grey market lenses from places like BHPhoto and had them serviced here. So long as you are paying and the lens says Nikon they appear happy to help.