There's now quite a few Stack Exchange sites that are in public beta on Area 51. According to the Web Applications proposal, the "site's progress will be evaluated in 15 days" (as of this writing), so the "evaluation" is coming pretty soon.
Apparently the criterion for evaluating a public beta is not set in stone. But once a site passes evaluation, what is involved in making a site "a full member of the Stack Exchange Network," exactly?