Will Windows Phone 8 run on Windows Phone 7 devices?

Microsoft's Windows Phone 7, launched in 2010, represented the company's latest efforts to make a dent in the smartphone industry. In 2011, Microsoft launched a major update, Windows Phone 7.5 (Mango) that could run on existing Windows Phone 7 devices. The next update, code named Tango, will be released in April and will again run on those same devices.

But thoughts are already moving towards Windows Phone 8, code named Apollo, which will be the biggest update yet to Microsoft's mobile operating system. One of the big questions outstanding is will Windows Phone 8 be made available to current Windows Phone device owners.

In a Microsoft published transcript of an investor meeting this week at the World Mobile Congress, the current head of Windows Phone, Terry Myerson, was asked in a Q&A session if a Windows Phone 7 user could update to Windows Phone 8 with a simple download. However, Myerson dodged the question, saying:

We just haven't announced this product.  So, it's kind of -- I can share what our application compatibility goals are, and applications have been written and published in the marketplace today.  The same applications to be able to download it in a future release and run.

So the message seems to be while Microsoft is promising that older Windows Phone 7 apps will be able to run on Windows Phone 8, there still some question as to if Microsoft will offer Apollo for older Windows Phone devices.

In the same transcript, Myerson also takes a shot at both Apple and Google in terms of offering new versions of their iOS and Android software on older smartphones. He states:

Statistically speaking, no Android phones get upgraded, none, ever. They have big bugs, they don't even get patched.  That's what we're seeing statistically out there.  In the case of Apple, they've shipped OS updates to hardware that makes it unusable.  It's a great hardware sales tool as far as I can tell.  Install this OS which makes your hardware unusably slow, so then you feel compelled to go back to the store and buy a new piece of hardware.