I hate to throw another wrench into this thread, but I wouldn't count Windows Phone 7 out either. It's still pretty immature, but it's an extremely slick, functional interface. I used a Samsung Focus for a few weeks awhile back, and loved it the whole time I had it.
I was wondering about that. I need to try one at some point.
The biggest benefit that Apple has right now is the depth and quality of apps. Everyone else has to play catch up and that is very hard to do.