If imitation is the best form of flattery, than there are three UIs that the entire industry should be studying to no end: that of iPhone’s OSX, Pre’s webOS, and Hero’s Sense. Nearly countless themes, ROMs, and elements inspired by these handsets have sprouted up in unlikely places, and Sense seems to be the greatest source of such buzz at the moment. When people start hacking their iPhones to act like your device, something big is happening.
This is the best advertizing a company could hope for, in my opinion. And all it costs is a little freedom.