Categories are indeed a great thing; I love the fact that 4.5 bboards integrate them so nicely.
But I can tell you from experience that when I send a non-programmer to openacs.org, they aren't sure where to begin to figure out what's happening. I send them to the bboards, where they can ask any question (as I tell them), and they're confused by all of the technobabble.
While I think that there's room to improve the marketing of OpenACS and its image to the decision-makers, part of my role as a consultant is to explain things to my clients, and to tell them why one solution is better than another one for their particular needs. So yes, it would be nice to have a more manager-friendly site in many ways (see zope.com vs. zope.org for a clever way of dealing with this) -- but it doesn't disturb me terribly that such a thing doesn't exist, because it gives me a chance to explain things in person to clients.
But this attitude breaks down when non-programmers are actually using OpenACS in their work and have questions. They could turn to me for answers, but (a) that gets expensive, (b) it doesn't help the community, and (c) they have to actually catch me when I'm not working on another project, which is a rarity nowadays. Besides, I keep touting the fact that OpenACS makes them independent of any particular software company, emphasizing that they can learn and develop without being dependent on me.
The bottom line, then, is that I would like to see a forum for the people who are forced to use OpenACS, but who don't have the time, inclination, or training to learn SQL, Unix, or even Emacs. The graphic designers I work with are very creative and clever, and do more with Photoshop and DreamWeaver than I ever could. But they're scared of programming, and don't want to have to wade through postings about Tcl, CVS, and the like just to find out how to change the background color in a default master for a subsite.
As for fragmentation, I'm not sure how much we need to worry about that, given how much the community is growing. Five forums for 10 people is kinda dumb, but five forums for several thousand users isn't bad at all. And when you prominently offer full-text search through all of the bboards, that strikes me as pretty reasonable.
