Change can be good, but as already mentioned, in this case, change costs money. Planting ads on the site is tricky to a degree, because it can turn people off and how much is too much before the page starts looking "too busy"? I don't want to log in and get bombarded by ads for dating sites and boner pills.
I think they should merge the boards already, simplyMax is as dead as a doornail. Host some challenges (even mini ones) that get front page promo instead of being tucked away in the corner along with the rest of what is going on in the community, pick up some more traffic in those lounges. Maybe the winning piece(s) can get a few days on the frontpage (assuming that there are rules for defining "finished" work) or even just for fist bumps and high fives, give people more incentive to not only join but to finish and actually stick around. And just to pretty much let people know that there's stuff happening here, it might bring some lurkers out, might turn the "hit & dips" into regular visitors.
The current medal idea is good but what do they mean when there is a challenge only every once in a blue moon (probably why the size of those medals didn't become a problem yet).
Speaking of lounges, I can understand the need for "Announcments" right down to "Battle Arena" with the exception of the newbie lounge because frankly, everyone is using it as a general lounge. Anyways, I don't see why Polys and Nurbs are separate, same goes for "Lighting, Camera & Rendering" and "Mental Ray". Maybe "Animation" and "Dynamics & Special Effects" should be one as well.
As Raphael mentioned, SM might need a rebranding, workflows have changed and if the site is offering tuts featuring said workflows then it might need that overhaul.