As our site evaluation showed, we have a few question topics that need clearing up.
What are these topics and how can we improve them?
Are there tags or subjects that need more attention on the site?
Are there games we don't cover well enough?
The perception around the gaming community is that rpg stackexchange is largely weighted towards D&D 4e. Largely because of the sheer number of D&D 4e related questions that the inital user see. It is a bit unfair as questions for other editions and games get promptly and accurately answered.
Something on the site that explains the situation and reminds newcomers that it has been useful for a wide variety of RPGs would probably help a lot.
Further to Rob's observation about 4e swamping our front page and the perception that creates for visitors:
I would love to see a public-facing, non-logged in page in parallel to our main page that hides question with certain (community- or mod-chosen) tags. It's easy for me to see that this site is useful to non-4e players with all the [dnd-4e] tags on my ignore list and the "hide ignored tags" option on, but new and casual visitors who never make an account will never get that view. A parallel front page that shows off all our non-4e content would go a long way to turning those visitors into repeat visitors or even users.