The vast majority of ideas anyone will mention will all fail a miserable death. And at the same time, they would hurt the forum whos members leave to the new forum.
There must be a critical mass of people using a forum to make the forum viable. Too few people and posts go unanswered. Unanswered posts mean new people abandon before becoming long term members. Old members get frustrated and leave. Etc.
Look at the Peripherals forum for example. Just 212 threads active. On the first page there are multiple posts with 0 responses even though they are days old. Of the posts with responses, there are frequently just one post with an answer like "I don't know". Posting in Peripherals is a waste of time. Just post it in general hardware and you are bombarded with useful replys - and you are right on topic as peripherals are general hardware. Or for a second example, look at the highly technical forum - a whopping 5 threads with posts today.
How many of you actively browse these little forums? I bet not many. When that happens it just hurts Anandtech - and we gain nothing from having all these unused forums.
I've seen it happen before. Great websites turn useless from too much subdividing. Soon no one goes there anymore.
Of course forums where you post banned items will be a huge hit - but that certainly won't be made anytime soon.