It feels like a million years ago that they gave us a sneak peek at the prototype for this, but they finally formally announced their new WiFi phone today. The F-1000, which'll let you make VoIP calls from any WiFi hotspot using your Vonage account, is made by UTStarcom and should be available sometime around spring or summer of this year. (We'll have a pic for this soon).
UPDATE: Found one! [Thanks, Jacob]