Think of this problem as you need to give one NAME for internet users. As we all agree you can't give one IP as this limits availability and is at the mercy of your circuit availability. By changing focus the issue then becomes how do you resolve tha...
How about using the GSS in addition to a local load balancing device? This seems to present a solution to this problem. There are other technical details involved, but GSLB is something that can help here.