Probably a way that would work a lot nicer for categorization would be a tagging mechanism instead of the rigid hierarchy as in those other forums.

For example when you created a thread you could also specify a tag for it, or a moderator could assign one later on too.

Threads would still be posted in one big list as they are now, but you could go to a tags list and click on a tag to filter the threads list to only contain ones that had that tag in it.

That would actually be a much more modernized organization method than what is used in those other forums.

Of course it would take some work to implement that, and I'm not at all convinced that it is an actual pressing need currently.

But that certainly comes to mind as a superior approach. For example see http://stackoverflow.com/ - that's newer type of discussion site and it is organized like this, the main UI is a linear list of topics but there is a tagging system set up that lets you narrow it to different categories.

Additionally a tagging system can be more flexible because you could assign several tags to the same thread. With a rigid folder type system the thread can only be in one folder.

- Michael