I can confirm this was not a DDoS, and we are actively working to fix the issue right now. We'll be updating our status page as soon as we have more updates to deliver.
I understand, and I don't have an ETA quite yet, but it appears that service is already starting to return. I've tested my domains hosted on Linode and a number of others that I know are and they appear to be working now. We're still working asap to ensure everything is coming back appropriately.