Ok, I admit it. Having lurked here for the past 3-4 years without contributing much, here goes:
Enough with the color/style/avatar suggestions already.
Content is king - even (or especially) at Webmasterworld.
My top suggestion would be to set up some kind of interface where visitors can be directed to answers in a knowledge base automatically whenever they ask the same questions over and over again, i.e., "Oh, noes! My pagerank dropped ..."
...and then leave the forum open to more pertinent discussions like the May Day update or the Google Adsense share announcement.
Finally, everyone should have a 10 minute limit on the site before they get booted off.
"Sorry, you've timed out. Get back to work, slacker." :-)