APC magazine quoted Natasha Kwan, general manager for Microsoft's Mobile Communications Business in the Asia-Pacific region, as saying that existing phones won't be upgradeable to Windows Phone 7.
In a statement, Microsoft said it could not confirm that any current Windows Mobile phones will be upgradeable.
"For Windows Phone 7 Series we are enforcing a strict set of hardware requirements to ensure a consistently great experience for end-users and developers," the company said
"While we cannot confirm that WM6.X phones that satisfy those requirements will be upgradeable, every Windows Phone 7 Series device will be upgradeable with improvements and features we deliver with subsequent Windows Phone 7 Series releases."
"That seems to be their default response these days," said Matt Rosoff, an analyst with Directions on Microsoft.
"They don't want to talk about backwards compatibility, and I suspect the reason is because the news is not going to please their partners and current customers."
Rosoff doesn't think that any current phones will be upgradeable to Windows Phone 7.
That fact may hurt sales in the short term, since some customers will likely decide to wait for Windows Phone 7 phones to come out rather than buy current-generation phones.
"I think they'll have a hard sell for the next six months," he said.
Still, Microsoft has made a good decision, Rosoff said. "It was the right thing in the long run to start from scratch," he said.
That's because Microsoft was able to offer more innovative features in Windows Phone 7 without having to build on the legacy versions of the software.
The Windows Mobile community may be further disappointed by changes that will impact developers and thus applications for the new platform.
Microsoft is also not saying much on this issue, but many onlookers believe that applications for the current Windows Phone software will have to be rewritten for Windows Phone 7.
That's in part because the community expects that applications for Windows Mobile 7 will require that developers use different tools, such as Silverlight, than they currently do to build applications.
Microsoft hasn't aggressively pushed its new Windows Mobile Marketplace, so the changes might not have a huge effect, Rosoff said.
The Marketplace has around 800 applications, compared to Apple, which has more than 100,000 apps in its iPhone App Store.
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