I don't know if I buy that it's all DDOS, I think influxes of new users and people constantly trying to log in on top of whatever DDOSing was done is probably what kept things down and now we're looking at them having to try and get things running as a ton of people keep trying to get on.
I was pretty disappointed by the whole thing since I got a PS4 & Destiny for Christmas and was left out in the cold.