Existing Windows Phone 7 devices will get updated to Windows Phone 7.8, not Windows 8by Brian Klug on June 20, 2012 2:00 PM EST
Looks like some of the earlier rumors about the upgrade path for existing WP7 devices turned out to be true. Microsoft just now announced that existing WP7 devices will not get updated to WP8, instead they'll get WP7.8 and a partial update feature set, including the new home screen with customizable live tiles.
We're still waiting to get more details about what other features make it over. Applications made for WP7 and WP8 will continue to work on WP7.8, but users wanting all the rest of the WP8 features will have to get that update in the form of new hardware. Update: Microsoft has clarified, and appliations built for WP8 will not run on WP7.5/7.8 (native C/C++ appliations), we're asking for more details.