The only reason I could see them bringing the servers down after early access would be for some kind of launch thing at Gamescom. It's a bit harsh on all the EU fans who want to go see what will be the last pre-release presentation and meet-up (though I suppose there might well be something in Tokyo on the actual day) if they're torn between that and early-access. I'M TORN!
Having said that, Gamescom is speculation. Perhaps they'll do nothing there special for ARR. I'm only thinking they will because they had a huge booth there for 1.0 and the timing is so close to launch.
