Microsoft: Windows Phone 8 will run all your old Windows Phone 7 apps

"Any app built today will run on next major Windows Phone version," Microsoft's Brandon Watson wrote on Twitter in response to a rumor from the usual Russian blogger suspects.

Watson, however, also added that Microsoft was "pretty clear about this" fact in its MIX'11 keynote address. I've scoured the keynote transcript but can't find that reference, so it must have been subtle indeed. But it seems unlikely that Microsoft would have even mentioned a Q4 2012 deliverable in a speech from April 2011, given that it was promoting its late 2011 release, codenamed Mango, at that time.

WinSupersite has the info HERE!