Now how about splitting the "macbook, macbook pro" forum into two separate headings?
There's not really enough product differentiation. They're of the same family or class of machines. The only reason the Air was broken off (and as
Arn said, maybe only temporarily), is because of the high level of specific, unique interest.
Also, the more the forums get fragmented, the less "cross-pollination" of posts from members would occur, and we'd start to be actively removing much of the "community" feeling. I have to remind myself to visit the Mac Pro/Power Mac subforums from time to time already. I think the more we split, the more we lose a broader discussion/knowledge base.
The Forum Spy & New Posts features eliminate that split when generally viewing, though, but I don't know how many members use or don't use those, so I can't venture a guess as to whether more or less granularity is a good or bad thing.
Lastly, I don't know what the limits of vBulletin are, but there are likely some limits involved. I'm sure Arn has to carefully choose how far the forums cam be split for that reason alone.