I was just browsing through our documentation and stumbled on something which has got some cool potential.
This describes how to setup the vSphere side of things for a mirrored disk within a Windows 2008 Guest. Just imagine doing in-guest mirroring of your data while doing FT on the outside. This means you would be able to span multiple sites without the need for a replication mechanism.
I asked around and unfortunately this scenario is not supported today for vSphere FT, but it definitely has potential… Another way to solve this problem would be if we could somehow leverage the Mirror Mode driver that is used by Storage vMotion today. Once again, this is not available today and I don’t even know if people are working on it… just something that popped up and something that has great potential and seems like a small step.