Arrgh! :( Just this week I needed to do some emergency rearranging of personal infrastructure, and moved one nameserver to Linode Fremont, while the other nameserver is in Linode Dallas. I was fully aware that I needed a more diverse long-term solution, but I figured "What are the chances that both Fremont and Dallas will go down in the next week or two?"
Sorry, folks. I hate that my dangerous flirting with Murphy's Law is hurting other people.