In the keynote, Steve Jobs said that the reason they weren't going with 3G on the iPhone is that it is not as widely available compared to EDGE. Still, the United States is very behind on cell phones comparitively to what's out there. They've had things similar to what the iPhone can do in Japan and China for years (internet browser, 5+ megapixel cameras on their phones, video chat, etc.). I think that is why the iPhone may not be such a huge hit in other countries just because the technology is not necessarily new to them.