Here's how to do it in Windows, for any of you who still don't know what I was asking about. http://www.tedlansingphotography.com/blog/?p=287
On a Mac, not yet all the way through the chain, it appears.
Linux is struggling with it, you could probably make it work with Krita.
It turns out you can set PSCS5 and maybe 4 to output 10 bits per R,G,and B.
When you google this subject, you don't get much, and some of it is just as confused as this thread.
I'll probably get a wide gamut monitor anyway, since I've got a pretty big discount sitting in my account.
The gamut will be there even if the bits aren't.