What if?

I can't help playing the "what-if" game after reading this little article from the BBC news site. If Zheng He did indeed sail across the Pacific and traced out the american coastline and had he continued exploring the region, our neck of the woods wouldn't look at all the way it does now. Would the ancient Mayan, Inca and Aztec civilizations still exist (or would have existed longer than they originally had)? I can imagine Columbus bumping into a few Chinese explorers and falsely assuming that he did indeed land in China. What would have happened next? A battle royale between the Spaniards and the Chinese? Would France have bothered sending Jacques Cartier? And what if China won? Would I be half chinese now, instead of half french? What if...what if...