Nope. The technology that's used in FoxPro made it into a bunch of other MS proprietary products and for that reason alone I'm sure it won't be open sourced.
I doubt anybody at Microsoft at this time is even thinking about anything FoxPro related, much less putting it into a state to be put out publically. And what possible benefit would it be to Microsoft to have FoxPro opensourced anyway? It'd be more of a liability for them...
Further I've seen some parts of the FoxPro code base, and trust me having it open sourced wouldn't help much. It's ancient and patched over code that worked well for what it was and did, but it was a huge mish mash of technologies old and new thrown together in a very difficult to maintain manner, that was maintained by people who were intimitately familiar with the inner workings of that code base. Only a few people of Microsoft actually worked on that code base at the end (Calvin chiefly for the language, engine and COM pieces). Those people are gone and didn't pass on their knowledge to the next set of programmers...
There is a reason FoxPro stopped going further: The codebase wasn't ready for the next set of changes required to move forward as a platform. Making adjustments for COM was more or less the last hurrah of what was possible with that code base short of a complete re-write which for Microsoft didn't make sense since they had other priorities (first VB, then .NET).
FoxPro as it is today works and works well for what it is and does. It's going to continue to do what it does, regardless of whether Microsoft supports it or not. When's the last time you called Microsoft for support on FoxPro anyway? It hasn't mattered for years. The support cycle at this point is merely a contractual point without any practical purpose.
FoxPro's reputation as a dead language wouldn't improve if it were open sourced, nor do I think would there be many takers who would actually think about working on an open sourced version of Foxpro for improvements. The people who care about FoxPro are old school hardcore FoxPro developers - not C programmers that actually would have to work on this ancient and difficult C codebase to change and improve the actual product.
So, yeah, my best guess is: It won't happen, and if it did it wouldn't matter.
+++ Rick ---