I think it would be useful to put up some mock layouts before making changes, more doable now since you have a team supporting you! I think a general clean up is worth doing, but not sure there is a killer feature that is missing - but how would I know??
On advertising, if you really want to do a service for the community, level the playing field. Because SSC has always been pay per ad rather than per per click, it has always skewed towards the bigger players. We (us three musketeers) tried to make opportunities for the smaller vendors (especially the one person startups) but we had to weigh that against revenue needs. You don't have that limitation any longer and I think you can do some good with it. Competition in the SQL tool space is good for all of us, but it's hard to compete if you can't afford ads. Show us ALL the tools in the SQL space, or at least the ones willing to pay some minimal ad rate to weed out the ones that aren't serious. Ads are a lot more interesting if there is variety, so if you combined running ads from more vendors with a policy that they have to change ads every 3 months I dont think some ads would be bad.
And here's one more I always wanted to do but is exactly counter to the ad supported model - show side by side comparisons of products. Reviews tend to be more product intro's and they have their place, but it would be really interesting to see feature comparisons (full in depth testing probably out of reach?).