Been happening for a hell of a lot of people (Most outside of NA, playing on the NA server) over the last 2 days; no word at all from Square other than mumbling something about DDoS prevention (Which has allegedly been "happening" since June 16th even though this only started in the last few days).

I wouldn't hold out too much hope of anyone actually fixing it any time soon, I don't think they read the forums outside of the JP version.