I see that we are now past the 90 days of beta. I checked out the stats and most of them look good.
When do we find out if we are moving out of beta?
At the end of the day it's a judgement call for the Stack Exchange team. However, a major indicator for them are the site statistics on our Area 51 page.
If we can get each category to Excellent, then moving out of beta won't be too far away.
Also, please read When Will My Site Graduate? on the Stack Exchange blog.
SharePoint SE is one of those sites that was doing really well before it got hit with a summer slowdown. That's not unusual but there's a few other sites that came out in the queue to graduate before SharePoint. What we're watching for is a bit more steady growth before committing to a graduation date. Take a look at this blog post I just published.
What you can work on —
82% questions answered is "okay" but it is precariously close to the lower end of passable. SharePoint is such a good, custom fit for a Stack Exchange site, this community should definitely be able to do better.
A concerted effort to get those hardest-to-answer questions answered should help. But, after you exhaust all efforts to get your questions answered, this site might be a good candidate for a cleanup effort.
If there are a lot of questions which should have never have passed community scrutiny, now is a good time to start cleaning them up. This community is much stronger now, so it might be time to start a site-wide cleanup. If a question isn't worth answering (i.e. "unanswerable" as asked, or low quality), start ridding yourselves of that cruft. This is a very gross estimate — It looks like maybe the bottom ~5% to 10% of this site's questions are completely forgettable content that nobody would ever miss. Work at getting rid of that content that should have been removed long ago. That clean-up effort is best initiated and organized through a meta post. Go for it.
In the meantime, focus on keeping your quality high, look for opportunities to attract new users (like Joel's OS X Lion initiative here), and use those social bookmarks to promote your most intriguing content.
If you look at http://stackexchange.com/sites you can see a list that appears to be "ranked". We're up there with the sites that are out of beta, and you can see quite a few behind us that got de-beta-ified. I think percentage answered is the blocker - the StackExchange guy more-or-less said as much.
By the way, the main StackOverflow site has about 82% answered, by my calculations :-)