i really doubt the glyph will go live. It just seems wierd that you would have to buy a glyph to be able to be a tank. That would mean you would have to be atleast level 25 and pay a lot of money for it. Im guessing they are just using this glyph to test out the mechanics and if people respond well will add a 4th tree. Im sure i read blizz saying warlocks have changed more than any other class, wouldnt surprise me if this is part of what they're referring to.