I’ve tried to decrease the number of forums, however by splitting up most forums based on Revo or Evo, I ended up with a few more. That said, if you’re someone who develops on Evolution you can simply hide all of the forums in the Revolution categories (by clicking on the category name) and the other way around, so that would mean less scrolling.
This looks like a great start. We’re going to be seriously rethinking the way add-ons are installed and searched and viewed on the site after it’s relaunched. They’ll definitely be split by Evo/Revo. With that we have a chance to rethink how we handle add-on support. We will likely be swtiching to a different forum platform in the process as well so a more radical proposal is not in order, even so far as considering a complete reboot of the forums and locking the older one down as a searchable resource.
I would rather dump the forum categorisation altogether and simply use tags as a series of filters, with a date sort.
While I’d love to see this in practice, in reality I think few people would actually properly tag their posts. And our forums don’t support this structure to being with either. Further, categorization allows me to hide topics via the ignore boards addon. For lanuages I don’t speak or read, this is invaluable and saves me time on the forums.
Might this not be a good application of some sort of crowd-sourcing "game", like Galaxy Zoo or Phylo?
Neat idea, are you volunteering to code that?

It sounds like a fairly significant amount of work.