I signed up for the WoTLK beta version at blizzard when I saw I could, got invited a few days ago, already started testing addons. Seems invites are very random. So just keep hoping and sign up at blizz.
DF PTR is up so not a big deal; but would still like the opportunity to see the new systems and integrate my addons with what i can't see on PTR, i.e. the actual new content etc.
Disappointing their social platform communicator keeps dropping the ball on addon authors last couple xpacs.