Vigilant site visitor Eric spotted that Blizzard has this evening wiped posts off the official Bug report forum and left a maintenance message which simply reads:
Could we be getting incredibly close to the Beta going live as the Blizzard admin team get things prepared for your bugs and puts further systems in place to track bugs? It’s certainly starting to look that way. If you try to post in that forum now it asks you for a Beta License. Intriguing.