The worlds are technically open, but we've discovered a loading screen issue that we need to fix. Working on it and we'll let you know when the worlds can be logged into.
Yeah, I had the loading screen issue. Closed client and retried a couple times, then decided to switch to 32bit client and wala, load completed and I could sign in. Exited out, switched back to 64bit and load up and sign in were successful. I still spotted the file link errors, but it carried on past them and I'm in the game.