While this is neither an official confirmation from Microsoft, nor an official statement from any of Microsoft's ODMs, in a recent Twitter Q&A, Microsoft UK's director of the UK Mobile Business Group Alex Reeve answered to the following question: "Will customers that have recently bought 6.5 handsets be able to upgrade to WP7 if their device meets minimum spec?" that "It's early days yet, and that's really for our hardware partners to think about." So like in the past - with previous Windows Mobile upgrades - Microsoft plays the ball back to the ODMs but could this be true? Could a HTC , a Toshiba or any other ODM offer upgrades to Windows Phone 7?
The biggest question mark are the Windows Phone 7 Series hardware requirements, as initially asked. Because Microsoft hasn't unveiled the technical requirements for Windows Phone 7 Series devices yet and therefore it's hard to know if a device will meet them or not. It's rumored that a Windows Phone 7 device has to feature a CPU at a minimum rate of 1 GHz as well as featuring an e-compass and an accelerometer which is pretty much standard for today's mid- and high-end smartphones. While the HTC HD2 features the rumored specs, the Toshiba TG01 for instance hasn't an e-compass and a smartphone like the Samsung Omnia II, which has an e-compass, only sports a 600 MHz CPU. At the end of the day, the range of devices, which might be upgradeable to Windows Phone 7, is pretty narrowed.
Furthermore, Microsoft confirmed us at the Mobile World Congress, that Windows Phone 7 Series devices have to sport exactly 5 keys only: Start, back, search, camera and volume up/down. Not a single Windows Mobile 6.5 smartphone features the required button layout today which makes an upgrade again pretty unlikely.
Anyway, Microsoft might have re-evaluated the specs for a Windows Phone 7 upgrade of today's devices. We've seen something similar before where Microsoft introduced the Start flag hardware key as a Windows Mobile 6.5 requirement but allowed devices without this key - for instance the Toshiba TG01 - to be upgradeable to Windows Mobile 6.5 anyway.
Whatever the truth is - as Reeve said: "It's early days yet" and nothing is official or confirmed.
Cheers ~ Arne