I'm guessing it was a DDOS due to the amount of time the site was down - if it was coming from a single IP or single IP range they would likely have been able to block it off a lot faster.

TechCrunch is calling it a DDOS, but as we know accuracy isn't their strong point.

The traceroute in the article suggests a DDOS, because the network gets progressively slower through several stages in the route - implying that the attacks are coming from multiple locations.