I've solved it.
Here's what I did:
1) Put in my Adobe CS6 Production Premium install discs and re-installed the programs that I had chosen. All of them (except for the 32-bit versions of software that was available in 64-bit).
2) Let all of the programs finish the install. I believe that Premiere needs Audition to be installed first, so that it recognizes that it's there, and that's a natural progression when installing all of Production Premium.
3) That's it. I opened Premiere, and found that it could connect with Audition.
I just tried what you'd instructed. No joy. I have Creative Cloud and I have everything installed. Audition, obviously already being installed was fine so doing what you'd said I'd gone ahead and uninstalled premiere and encore then reinstalled. No joy, still greyed out, still crippled my workflow finishing up audio on a feature movie. Any other ideas?
Have you tried uninstalling all of the programs, and then installing them all again, Audition first?
I'm not really sure how it works if it's not a creative suite and all are being installed at the same time.
Exactly the same problem here with the Master Collection. I place a video file with embedded audio onto a track. I attempt to edit the clip with Audition but it's greyed out. I try an audio file on its own and attempt the edit again with Audition but still the edit clip option is greyed out and unavailable. Obvioulsy, with it being the Master Collection I don't have the option to dictate which prgrams get installed first. Hope a bug fix is ready soon.
With Production Premium, Audition definitely installs earlier in the install process than Premiere. I recommend just starting your full install process again, but don't uninstall anything first. Let it re-install all of the software on top of the current installs (uncheck the ones you don't want installed at all, obviously). That's how it worked for me.