Last week we heard from Microsoft that some Windows Mobile 6.5 phones may be upgradeable to Windows Phone 7 Series. This brought a glimmer of hope that more recent Windows Phone releases could be upgraded to the new OS. Today we are hearing the opposite from Microsoft, in particular about the HTC HD2's potential for upgrade.

Natahsa Kwan, General Manager for Microsoft's Mobile Communications Business in the Asian Pacific Region, said the HD2 doesn't qualify (for upgrade) because it doesn't have three buttons (the HD2 has five buttons). Kwan explained, "Because we have very specific requirements for Windows Phone 7 Series the current phones we have right now will not be upgradeable." There is some indication that the button issue may not be sole reason behind the HD2 not being upgradeable.

Tony Wilkinson, Microsoft Australia's Business Operations Director, has said that "there are some hardware components that the HD doesn't have." We are expecting Microsoft to reveal the core specifications later this month at the MIX10 Developers Conference.  If this happens, we should have a better picture of what may or may not be eligible for upgrade to WP7S.  Until then, the topic of WM 6.5 upgrades may become another marathon, "on again/off again" topic (remember the Zune phone?) for discussion.