Windows Phone Thoughts: WP7S: The Backwards Compatibility Story Thickens

"One final note at today's event is that Microsoft has now officially confirmed for the first time that 7 represents a clean break from Windows Mobile as we know it today; existing apps won't be compatible. Though that's likely to be a pain for existing owners with specialized apps who are looking to stay in the Microsoft ecosystem, Windows Phone 7 Series itself is a very different beast than the operating system it replaces -- it feels different, seeks a different demographic, and symbolically represents a very important clean-slate departure for a company that had lost its way in the mobile space. The bright side for the 6.5 faithful, we suppose, is that Kindel closes by saying that they "will continue to work with our partners to deliver new devices based on Windows Mobile 6.5 and will support those products for many years to come" -- a message Microsoft has been echoing recently."

In case you hadn't heard deduced this, our favorite third party apps won't work with Windows Phone 7 out of the box. Will this mean that developers will flock to technologies such as XNA and Silverlight to re-design their apps? Or do you think they may just leave the platform?