Apparently some IT firms did not study the lessons learned from Hurricane Katrina. What took out most of the phone system and the broadband/Internet networks in and around New Orleans was not the high winds and rain, but rising waters. Many of the network electronics were on high ground (e.g. upper stories of buildings, above flood waters), but the emergency generators were on the ground! The water rose and flooded all the generators, and the networks went dark.
So in New York, the same thing is happening. Major Web sites are going dark because data centers are having power and flooding problems. Anyone that puts a data center in a flood zone (and lower Manhattan is a flood zone) is nuts.
The second lesson from Katrina is that you may need all your data and servers fully duplicated at another location somewhere well away (e.g. several states away) from your primary server location. If the Huffington Post Web site is dark because of power problems in New York City, that tells me they don't have a disaster recovery plan.
As more and more stuff is stored online in "the cloud," there is a growing demand for data centers, and data centers that are away from coastlines, away from flood and hurricane zones, and near high performance open access fiber networks have a distinct advantage.