This is the concept behind the product but the product is not available yet... you have to wait 2009
Have a llok to this document, it should help you now :
Fault tolerance is not relevant to your storage. You can make set up online duplication and failover on storage level, but it will work even for non-FT VMs. Or not work.
If it works for non-FT VM, it will definitely work for FT VM.
VMware vExpert '2009