The question of whether or not today's Windows Phone apps will be able to work on the next "major version" of Windows Phone aka 'Apollo' or Windows Phone 8 was never a major concern for us as we just assumed they would work. We even saw a job description which said as much back in February.
Still for some developers there were lingering questions about Windows Phone 8 would have the same core as Windows Phone 7.x. While details are still very sparse to that former aspect, tonight on the Windows Phone developer blog, Microsoft's Larry Lieberman reaffirmed that indeed, today's app will work just fine on Windows Phone 8:
"With regard to existing applications: today’s Windows Phone applications and games will run on the next major version of Windows Phone. Driving application compatibility is a function of Microsoft’s commitment to its developers. Regardless of what we release in terms of new developer features and functionality, we have made a large investment in protecting your existing investments."
That is certainly good news and should allay some fears for devs. But perhaps what is even more interesting is we're getting the first hints that Silverlight may be de-emphasized for the next generation of Windows Phone:
"We’ve also heard some developers express concern about the long term future of Silverlight for Windows Phone. Please don’t panic; XAML and C#/VB.NET development in Windows 8 can be viewed as a direct evolution from today’s Silverlight. All of your managed programming skills are transferrable to building applications for Windows 8, and in many cases, much of your code will be transferrable as well."
To our ears, that doesn't sound like Silverlight will be a major part of Apollo (though it will be compatible) and from what we've heard from devs, that's not a bad thing at all. A more interesting reading is that Windows 8 and Windows Phone 8 will be based off the same bits, especially when Lieberman notes that "...targeting a tablet vs. a phone, you do of course, need to design user experiences that are appropriately tailored to each device."
There's certainly a lot of reading in between the lines in that post and makes some interesting discussion, so fire away in comments.