It was originally thought that some Windows Mobile phones would be able to upgrade to the new Windows Phone 7 Series, provided that they met the hardware benchmarks required by Microsoft. But when asked for specifics about that upgrade plan, Microsoft executive Natasha Kwan said that Windows Mobile devices – including the heralded HTC HD2 – will not be upgraded to Windows Phone 7. Despite the HD2 meeting the processor and display requirements to run 7 series, Kwan says it “doesn’t qualify because it doesn’t have the three buttons.”
All Windows Phone 7 Series devices are required to have three buttons: Home, Back, and Search. The HD2 lacks the dedicated search button, making it ineligible to get the upgrade. Further complicating matters is Microsoft Australia executive Tony Wilkinson’s suggestion that “there are some hardware components that the HD doesn’t have.”
An official upgrade path seems dead in the water, but I’d wager that enterprising folks at XDA and other sites will find a way to repurpose a hardware button and release custom ROM’s that put Windows Phone 7 on Windows Mobile devices.