Apple's warranty documentation isn't exactly clear on the subject. Their standard warranty states "If the product is portable, meaning that it can operate independently without a power cord, you may obtain warranty service worldwide." which would suggest the iPod is covered worldwide.
However there is also a separate iPod warranty which may supersede this definition. It doesn't mention anything about worldwide support but does contain this passage "FOR CONSUMERS WHO HAVE THE BENEFIT OF CONSUMER PROTECTION LAWS OR REGULATIONS IN THEIR COUNTRY OF PURCHASE OR, IF DIFFERENT, THEIR COUNTRY OF RESIDENCE
" Which could be interpreted to mean that the warranty extends outside the country of purchase.
It's all pretty vague but I would assume that you would be covered outside the country of purchase.