Just curious, what are the requirements for leaving the beta stage and becoming a full-fledged site like, say, English Language & Usage?
This is somewhat answered in a StackExchange blog post here:
The short answer is the requirements are that the site is able to be self-sustaining. This includes a steady stream of users, users with enough reputation to help the mods moderate the site, and when it's shown that the site contributes to "make the Internet better".
Quite frankly it is unlikely we will ever graduate. Before handing sites the keys to the kingdom they require that every participant sacrifice a banana on the Alter of Stack. This, of course, would be anathema to most of our constituency. Our common creed requires that we not bend the knee to any...
In all seriousness, we graduate when SE thinks we are mature enough as a community to make our way in the world and have enough traffic and quality content to be an asset to their commercial agenda (and ostensibly the internet).
Personally I think we need quite a few more people asking quality questions -- the kind that interest real experts in sticking around. I'm glad that some of you guys have stuck with it while we wade through the cruft, but I've seen a lot of the best experts wander away. Ironically the non-Christians are some of the most consistent participants.
Besides some more good questions and related experts, we need a few more folks (like you) that have enough rep and step up and take ownership. Rather than mods stepping in to close bad questions and edit poor ones into shape, those and other tasks should mostly be taken care of by the community. At the moment we barely have five people with sufficient rep to do things like Vote-To-close, much less that actively use their privileges.
Onward ho! (And save the bananas for the monkeys.)