I like WP7 but...
There are a few problems. I like the ui and all. I was trying out the demo that microsolft made for iPod users and everyone to try. It was quite a pleasant demo. But I dont think I could switch to a windows phone for 3 main reasons.
1. The hardware on wp7 isn't close to what is offered on my iPhone. I feel that the 4s is a perfect piece of hardware. Amazing design, screen, and cameras. The it feels great in your hands because of the size and material.
2. The app selection on ios is much greater and most apps come out first on iOS.
3. Apple's great support and the wide accessory support.
I just feel that those are the biggest reasons. Oh and the Ecosystem. Features like AirPlay and iCloud.