WinPhone (Windows Phone 7 Series...named by a committee, I'm sure) based on the ZuneHD. Hope this works well for Microsoft. The new ZuneHD, from all reports, is an outstanding device and beats the iPod Touch in every way but in the availability of Apps. If Microsoft maintains very tight controls over hardware, this will be a success (at least in a technological POV).
As an Apple and iPhone user, I cannot say I'll go out and get the new device, but, at the very least, the competition Microsoft is providing is welcome and will help push the market in improvements to all of the "Smart Phones" being sold.
Microsoft's official page
Link to FoxNews report on the device