My iPod Nano (7th gen) has got a radio with region options. I just realized that I never switched back the region to Europe after a trip to the US in the summer. Never had a problem with tuning to the Dutch station I usually listen to on my iPod at 98.9 Mhz.
I have no idea if having different tuning steps will cause problems in Asia with an American model. Apparently some people have experienced problems when trying to use a US tuner in India because of the different spacing of the steps.