Our Area51 page says that the site's status will be evaluated in 7 days. What's going to happen then? Is this "promote or shut down", or might the beta continue, or what? (I see the five criteria and our progress against them, but I don't know how that turns into a decision and what the likely outcomes are.)
This site will not be shut down in 7 days. The 90 day beta is a minimum requirement before a site can graduate. The vast majority of sites need more time to build up a critical mass of users, questions, participation, and traffic.
You can read much more about that process and what those Area 51 numbers mean here:
Make special note of the sections that describe what you can do to help your site get closer to graduation. Other sites have had a lot of success with these techniques.