Larry Lieberman made the information public yesterday, on the official development blog, where Microsoft's senior project manager addressed some issues regarding Windows 8, the existing SDK and nonetheless, Silverlight.
In Lieberman's own words, "today's Windows Phone applications and games will run on the next major version of Windows Phone". Microsoft's spokesman confirmed that the company was committed to developers all along and although new functions and options are brought by WP8, they will not affect submitted programs.
This move is more than welcomed, as more than 80,000 apps currently exist in the Windows Phone database, with even more to come in the following weeks. Microsoft opened the marketplace to 13 new countries a couple of days ago, and it's planning to extend that number in the near future.
The original post also contains information regarding Silverlight, an internet-based programming language used by Microsoft, which is going to be discontinued. Lieberman advises calm, as XAML and C#/VB.NET languages can be seen as a direct evolution of Silverlight in the upcoming Windows 8, with some portions of existing code being transferable across platforms.
Lieberman also claims that Microsoft is aiming for maximizing investments with every platform it develops and reminds that developers are working hard to sustain evolution. A proof of that is the latest WP SDK update, version 7.1.1, which makes the SDK compatible with Windows 8.