there were couple of discussions on MSDN forums, here and stackoverflow as well about using the "Managed C++" for WP7 development.
Even with Mango update the Silverlight or XNA applications are limited to C# or VB, it is still unclear if the C++ code which contains no dependency on frameworks can be compiled into MSIL library and be executed there - i have not tried it yet, but I can imagine that it will make my life easier if this will be possible.
Can anyone give there a clear answer? Just to be sure what I am asking - is it possible to compile application logic written in C++ into intermediate language MSIL (according to my understanding there is no difference in the result, whatever language is used (C#, F# VB or C++) when compiled into MSIL and the WP7 runtime will execute it) , separate it into DLL library and execute it on WP7?
Of course might be possible, that when C++ compiled into MSIL it will create some MSIL instructions, which are not supported by WP7 runtime, which can support only MSIL subset...
Having a very clear answer here will help a lot.