I played with Windows Phone 7 on an HTC Surround for the first time today. I love my iPhone and iOS in general, but man, I was very impressed with WP7 and enjoyed it a lot more than I ever imagined. I doubt I'll ever move away from iOS, but if I did (or wanted to try something new), I'd definitely go with a WP7 phone. Microsoft did a fantastic job in revamping their mobile OS and giving users something that didn't follow Apple's grid-based UI.