There isn't really anything I think we NEED at the moment, but I'll go ahead and list some of the sections that I see in other forums to see if they spark ideas for some other people.
Forum RPGs - A section for role plays. I've only joined my first one recently, and I haven't gotten the hang of it yet, but these are very popular on many forums. I'm not sure how interested users here would be though.
Random Stupidities/Serious Discussion/Rants - A section for stupid/spammish stuff. Our Misc. section sort of covers it in a way though.
Sales and Trading - For selling, buying, or trading supplies, projects, ect. (without having to sign up for an outside site, like etsy or ebay)
Be Creative (and stuff) - A section that houses writing, fanfiction, artwork (painting, drawing, coloring, spriting, compared to stitching, beading ect...)
Again, I'm not really suggesting these, per say, but I'm putting them in the open based on what I've seen (fairly) standard at other forums.