We have recently moved our secondary name server (ns2.islandnet.com) to Dallas, Texas so that DNS service for our customers' domains will be uninterrupted in the event of something like another fiber cut. No changes are necessary on the part of customers.
I am also in the middle of setting up a third name server (ns3.islandnet.com) in London, UK to add further redundancy. It should be completed by the end of the day.
These servers also act as external monitors, testing our network from the outside every 5 minutes and alerting us via SMS if anything is unreachable.
Update: 12:31pm ns3.islandnet.com in London is now online.