I've been wondering for a while what it would need for the site to leave Beta. We seem to have an excellent ranking for most things except questions, which is definitely improving.
So what's left?
As Torben mentioned, our questions per day statistic is the one statistic on Area 51 that stands out.
However, I believe that those statistics may not be the only thing they consider when evaluating whether a site is ready to launch.
There are aspects of participation that don't translate directly into the Area 51 stats, and I am a bit worried that we are behind the live sites in those aspects.
We have 90+ people who have enough reputation to cast close votes, yet I cannot recall seeing a single question that has been closed without a moderator assisting (for those who may not be familiar with the process, closing a question requires 5 users with sufficient permissions, but a moderator's single vote is sufficient). While this could be a case of us moderators being overzealous, I've waited for a day or two on several questions that were clearly off-topic, and still the most I recall seeing were 3 users casting close votes.
From what I see in the live sites, questions that clearly need to be closed get multiple close votes very quickly, and maybe half of them get closed in an hour or two, without a moderator needing to step in.
More concerning, however, is our meta participation.
It feels like our overall meta participation has faltered in a big way.
For the most part, meta mostly sees activity when we get a new user who has questions, when someone is unhappy with the site policies, or when moderators propose and discuss maintenance or other site-related issues. Participation in those cases seems to involve just a handful of users.
As an excellent case-in-point, we were recently asked to participate in a self-evaluation. As part of the self-evaluation, we were encouraged to vote and comment, to actively discuss how well or poorly the selected questions reflect our community.
It looks to me like we got 4 people who actively participated, and only one single user besides the moderators followed through with a comment as requested (thank you deworde, btw!).
Maybe the Community Team isn't looking at anything besides the Area 51 statistics, but I believe that an improvement in our overall site participation, beyond simply asking, answering, and voting, would go a long way towards helping us graduate.
EDIT: Here's a great opportunity to help move the process along! We've been asked to participate in another self evaluation of the site! It would be great if we could get some more votes and especially comments to demonstrate participation in the process!
The Area 51 dashboard indicates that the site status is "excellent" except that our 2.3 questions per day "needs work."
We should raise this to 10 or 15 questions per day - then we'll probably launch!