I do not think that the DO is a sentient being in the traditional sense. I hold to my old theory that Ishy has been the force at SG since the beginning. He is the Avatar on Earth with the "spirit" of the DO manifested in him. That is why he is so attuned to the DO's philosophy. Ishy and the Dragon have been waging this eternal struggle, them, the Avatars, the physical manifestations of the DO and the Creator. That is why we haven't heard a creator, because "it's" way of taking a hand is the pattern, and it uses focus points on the pattern (taveren), to more heavily influence events.

Flaw to my theory u say? because we have seen the DO's voice in peoples heads? Well conveniently we haven't seen it in Ishy's head. And Ishy I believe has been entering the minds of the forsaken with the TP since the AoL's.

On another note I think the analogy of the DO pouring out would be a big yes he would have to pour out into the world, he is a spirit and therefore is everywhere in the pattern at once like the bore it is everywhere and only SG is like a focus point for it. Therefore the DO is either everywhere he can exist or nowhere at all. So when the bore opens again he will simple be everywhere inside and outside the pattern at once.