the reason for most of us to employ virtualization is multiple workloads with a mix of charcteristics on a single box. Which causes strain on cache efficiency of the cpu, memory - cpu transfer, etc.
tpc does not reflect that situation very much... the ibm benchmark is imho thus interesting, in that it proofs you do not *have* to go for bare metal for proper performance......
however, the list price tag of vmware ( KVM being almost non-existent in enterprise use)
and to a lesser extent Xen-from-citrix, might still be a good reason to not virtualize such a tpc oltp workload...
I wonder (didnt check) what stops vendors from doing the tpc vm benchmark or cook one themselves, that properly reflects mixed workloads in a slightly realistic setting :-)
a beer is in order, I think :-)