Will your old Windows Mobile device be upgradable?
"Because we have very specific requirements for Windows Phone 7 Series the current phones we have right now will not be upgradable."
The interesting part about this for me is that I was surprised to hear last week that Microsoft was giving control back to the hardware partners. After all, one of the main principles behind Windows Phone 7 Series is that Microsoft has its "chassis specs" and that hardware partners are not allowed to design something different from the spec. I have yet to see any Windows Mobile 6.x devices with Home, Back and Search buttons, for example, and therefore would have said that there wouldn't be any in the market currently that could upgrade.
With the above in mind, it's interesting to note that HTC's HD2 (pictured above) does offer a Home and Back button, but there's no Search button currently. That said, there's a Windows button that could easily be reconfigured with some cooked ROMs or even HTC's help, if the company was so inclined.
So, in summary it looks like there won't be official support from Microsoft on upgrading your existing 6.x device to Windows Phone 7 Series, but some hardware partners could still come up with an "un-official" solution and provide an upgrade path for a device that's already in the market.
One more thing: I reached out to my friends at HTC and their official comment is:
"it's not appropriate for us to issue a statement at this time."
I can appreciate the above comment, given that each week it seems someone from a different part of Microsoft is changing the rules. Perhaps next week someone from Microsoft in the United States will confuse us yet again?