Thanks for the interesting question. None of us on the C++ AMP team have any experience with AudioProcessingObjects, but it sounds like an interesting scenario to look into (thanks for the pointer).
To your question, there's no particular reason I can think of why you could not use C++ AMP to implement an APO DLL. From what I can glean from a quick glance at the MSDN documentation, the actual audio data that gets passed
around is just an unstructured blob. Please bear in mind that C++ AMP only supports a subset of the fundamental data types that C++ does... in particular, "char", "short", and bitfields are not supported. If the audio data contains any of
these types, then it may be difficult to represent it on the device, or it may require that it be transformed into a C++ AMP-compatible format.
I'd encourage you to try it out and post back on your experiences with it.
++don;
