Business 2.0 On May 7, Google (GOOG), perhaps the most indispensable online utility, went offline. Its dependents were immediately complaining in every forum they could find about their lack of access to search tools, Gmail accounts, and Google News. When Google came back online, after a mere 15 minutes, a quick investigation proved that the culprit was the domain name system, or DNS. continue reading at Business 2.0 website.
I would have to say this is pretty off the mark, technically. The size of the internet and the domain name space has doubled many times over without putting any particular stress on the DNS system. What is a concern is exploits like DNS poisoning and coodinated DDoS attacks on the root servers.