T-mobile 3G
http://online.wsj.com/article/SB117815938377190497.html »
http://www.theonlyphoneyouneed.com/ »
Two of the phones that T mobile has lined up for it are the Samsung SGH-T709 and the Nokia 6136 witch use UMA for the Wi-Fi. The downside on both phones is they loose bluetooth but I'm sure newer phones will work around this issue.