The official response from Rebecca Chernoff is they're waiting for participation to reach a tipping point. So be thinking about how we can promote the site and how the UX of the Area 51 page can be improved to communicate what really matters.
Update: The SciFi site just launched, putting to rest any doubt about whether the stats on the Area 51 page have anything to do with when (or indeed if) we'll graduate.
UX 2.9k questions 11.0k answers 99% answered 8.6k users 2.1k visits/day
SciFi 1.8k questions 3.9k answers 96% answered 3.4k users 1.6k visits/day