Velian voted 1 on this story.
This is a good story and a good topic, but not a good idea.
"Please don't do this" is my response to this idea. Unless I misread, that idea would basically do the site in. Not only would these forums go incredibly off-topic, but it'd discourage people from bothering, it'd confuse people, it'd eventually have way too much activity (even with the decreased audience), and worst of all, it'd make it so people would have to write, "STORYNAME: Normal post topic here," which would lead to suggestions for, uh, our current system.
But, I do like the idea of general forums. I'd like to see the "What Now?" thread renamed to something like "Ideas For Improvement" or somesuch, made permanent, the link made more visible and possibly even coded a little differently than article threads (a permanent forum might need some different features).
Slashdot desperately needs a place to discuss certain topics (ex: "what to do about hot grits"). Yes, a lot of people know about the creation of hidden sids - but normally the only way they ever get much traffic is from people who advertise them in their .sigs, and that's not many people... who advertise them, or see the advertisements.