The stickied thread was meant to serve as somewhat of a directory of that nature, although its effectiveness is obviously rather nil at the moment. I don't have much free time in the very near future, but perhaps in another week or two I'll be able to try to piece something more current and useful together. I originally envisioned a setup where someone looking for voiceactors could go down the list, check out samples, and actively recruit people they felt fit certain roles; if I can get a bit of compilation together, maybe the thread can finally serve that purpose. I have a rather substantial amount of personal file-hosting space, so I could theoretically help anyone whose only other option is a temporary site.
Beyond that, I don't really know that much organization is necessary, or even possible. I don't know that the label "active" works at all; most people post in here saying that they're willing to do voice work, and I'd assume that they would if asked to take on a certain role, but beyond that, there's not much to be active at. I'd also want to shy away from lumping certain people together as "actors;" I may have done a few voice roles myself, but I don't consider myself an actor by any stretch of the imagination.

Assigning that label to people presumes that those people are part of some specially-skilled group, when the situation is very much one in which everyone can (and should) help out with campaigns if they're willing/able to do so.