Back when work on the new forum software was first announced, suggestions for a more effective forum decomposition were rejected on the basis of "Let's wait until we have it in place". Well now we have it in place, so it would be good to start hearing suggestions. Since there will be literally millions of Pi users in due course and this site is likely to become a popular destination, we had better do something about the current very threadbare decomposition before weight of numbers makes finding what you need like a needle in a haystack.
Currently we have only two forum categories, "Raspberry Pi" and "Projects and Collaboration". This misses at the very least a category for meta-discussions, such as discussions about improving the forum for example. "Meta-Discussions" is a possible category name in its own right, although some might not know what it means so it would be good to hear alternative names suggested.
Under the meta-discussion category (whatever its name), useful forum names might be "Raspberry Pi Forum Users Help" (a help forum for helping people get the most from the phpBB3 forum software and its features as implemented here) and "Raspberry Pi Forum Development" (a forum for suggesting new phpBB3 configs and styles for the forum and discussing pros/cons and implementation issues).
We've already seen the need for this in just the few short days since the new forum went live. A user (not me) made a forum feature suggestion and an admin responded but immediately locked the thread without giving a reason. I assume that the reason was the perfectly logical one that Raspberry Pi -> Features and requests is the wrong forum for such a request because "Raspberry Pi" was the wrong category of topic for that post. That is indeed true, but the user had no option because an appropriate category does not yet exist. It's just one example, but many others could be given.
Where most work will be needed though is in the main "Raspberry Pi" category, which has only 4 forums and a wildcard catchall. This needs a much more comprehensive breakdown to help users partition their posts and focus their interests more meaningfully. The very small number of forums in this category results in the visitor being confronted by a huge deluge of posts on subjects of all varieties, the vast majority not appropriate to whatever the user was seeking. Even worse, because the small number of forums results in such a wide variety of thread topics, many of the threads that would have been helpful to the user are lost off the bottom, pushed into oblivion by threads that are of no interest to that user.
This is going to become a major issue because of the very large audience served by the forum, so it deserves a good deal of thought and planning to impose organization on the sheer volume of posts and make them useful to people when they come here.