Bornakk announced last night that we can expect what could be a fun change for this and future PTRs: the US, Korean, and EU servers will share test realms. We might speculate that this could be delaying the release of the PTRs despite the fact that we have the notes and the patch in hand, though it is, of course, possible that it's the problems with the live servers right now as well.
Regardless, it'll be interesting to see how this changes the test dynamic as testing goes forward. There's been some questions in the past over which region's raid groups are better, so it might be fun to see if they decide to duke it out over the new Sunwell content face-to-face. It might be fun to see if some multi-region arena tourneys get set up as well. Even on the casual side, some of us have overseas internet friends who play on different servers than us by necessity, so it should be great to meet up with them and kill a few monsters or do a few dailies together.
Of course, before we get to see if anything fun comes out of this, we'll have to make it on the PTRs. We'll be sure to tell you as soon as we see them up and running!