It's not perfect since everything is not replicated in both datacenters, but the business would continue. The hurricane in 1996 knocked most communications down in Mahwah (the datacenter was powered by generator but most data circuits...even oc-xx was down due to multiple telco centers being under water) and everything was run out of windward. Windward had a minor power problem earlier this year and a lot of things were run out of Mahwah. Router problems force communication to either datacenter frequently. The biggest issue is apps, databases and external customer connections.
I don't think we could help BP much, but I was wishing every day after Katrina that UPS wouuld take over food/water/shelter distribution and logistics!