AU on Windows? Not as far-fetched as you might think...
As a developer, something like the following (which is in the AU SDK) can really give you the heebie-jeebies:
mRenderThreadID = pthread_self();
mRenderThreadID = GetCurrentThreadId();
The thing to note is the #elif TARGET_OS_WIN32 line. Why would there even be a mention of Windows in the AU SDK? There's no reason for it unless someone at Apple is working on exactly that. Food for thought, anyways. What this really gives creedance to is Adam's theory that Apple will ultimately release a customized version of Windows and call it a day.