According to APC, current Windows Mobile 6.x phones will not be compatibile with the upcoming Windows Phone 7 Series. In order to run Windows Phone 7 Series on a phone, the device must have three buttons (back, start, and search).

Now some people are asking whether the HTC HD2, which has more than three buttons, will be able to run the upcoming mobile operating system. According to Natasha Kwan, the General Manager for Microsoft’s Mobile Communications Business in the Asia-Pacific region, the HD2:

“Doesn’t qualify because it doesn’t have the three buttons.” In addition, Business Operations Director for Microsoft Australia, Tony Wilkinson, says there’s more to it than just buttons. “There are some hardware components that the HD doesn’t have.”