Yeah, it is enticing, but I'm still a bit uncertain. I like where they're going with this, but I wonder how closed it will be...obviously less than the iPhone, but Android? Who knows.
As for the UI, I actually think iPhone is the worst currently. Well, apart from the stock Windows Mobile one, but I don't think anyone actually rocks the stock interface - skinning is one of the main benefits of going Windows Mobile (or at least it makes your phone usable).
Many of the stock applications on the iPhone are designed wonderfully, but the UI of the system as a whole just doesn't do it for me.
Honestly, I think I'm leaning more and more toword Androd every day, but I will probably wait and see how Windows Mobile 7 turns out.