I'm not sure it does. They said it would six months ago but I don't see anything about it in their release a couple of days ago. It might be nice but I don't see it as important as the other factors.
I'm pretty sure it does, google "amd seattle freedom fabric"... Plenty of mentions, and none saying it's been dropped.
As to it's importance: Remember, AMD is already selling SeaMicro-based servers (yes, even with Intel Inside.) Now they'll have a chip that enables a new class of processor cards that don't need the off-board fabric chip, etc. I.e. cost and scaling benefits and grabbing all the server margin.