We won't have an exact release date until we're confident that it's completely ready for showtime, which also entails server owners being prepared.
However, since there's been a lull in bug reports and changes to the code, Thijn is correct, this is very much a release-ready version. We've also released the server anyway, so there's no way for us to "end" the beta other than by releasing a full version. The servers don't have killswitches in them.