The normal servers going down is normal. The take-down of the account creation servers is what has me psyched. It means that those servers are being re-tooled and reassigned for better things.
You heard it here first! I predict, based on what I've seen (which is totally outsider information and a few gut feelings), that Open Beta will begin on Halloween. Think about it. It's two weeks before the "middle of November", with two weeks being the predicted duration of Open Beta. The account creation servers are going down Friday. Even when retooling the servers, Blizzard hasn't kept its servers down for more than a few days max. That would mean the servers will be ready on Monday. Ready, that is, to accept applications and create accounts. One week sign-up period for Open Beta means that Open Beta will start on October 31/November 1. Plus: Blizzard is a gaming company with a sense of humor. They like to have fun. Releasing open beta on halloween is funny.
There's an unbroken chain of circumstantial evidence here. My prediction, once more: Oct 31/Nov 1 for open beta.