Hey wpcentral! Really excited about Windows Phone, especially mango. I realize that mango won't be available until the fall, but I'm ready to switch now. I'm on att, and I'm looking at either the focus or the HD7S. My question is, if I take my sim from my iphone 4, put it in adapter, then put it into the hd7s, will it work? Also, will I be able to keep my unlimited data plan, or will I have to give it up?