There probably just migrating accounts over to there new system. chances are it will all be sorted out for you soon enough.
EDIT**
I never signed up to this and I know they delayed it at first. Just tried signing in and got the same message shawty. My guess is they will have it sorted out in next couple days just keep and eye on it
EDIT2**
Just tried anything and you get the same message. I tried to login as jim didnt get any No account exsists etc etc just same server down message so looks lik its completly offlline for now.