The problem persists almost 24 hours later.
Still can't progress the Omega quest line.
I have tried other instances, DF and GH to be frozen leading to my inability to play at all.
The only thing I have done is gather and craft but there is a limit to how much you can/need to do when you can't do much else in the game.
It's like they don't even want peoples business!
I appreciate that it is an American holiday but for a worldwide service they have fallen far short of the mark for good customer service.

These DDoS measures may be the root cause but it also must be said that multiple accounts logging in for a new release/returning players/routine players logging in for new content is to be expected.
Multiple legitimate logins also look like a DDoS 'attack' so in effect are they just punishing/restricting the player base for wanting to play the game they subscribe to and have purchased