I would love a sub forum for ATC. I used to fly with an ex ATL center controller, and I learned all sorts of things. It was valuable conversation.
In addition, controllers are all trained to a very high level. They are all "ATP's" so to speak. They really are well trained professionals that would have a lot to offer.
I for one would read the forum, and at times have questions for these specialists.
I would like to see a "sticky" though that encourages people with a question about a specific event or activity to first call the ATC facility involved. Over and over here I see threads that begin with something like "does anyone know why the controller did ... ?" where the question could be easily answered by calling the facility. Absent the phone call the OP gets lots of guesses, usually fairly high quality but still guesses, where he could instead easily get the facts.
After calling the facility, if its an interesting situation then go ahead and post. We all learn from this.