Hi there,
We use VMware a lot. It does work very well indeed, you can have lots of virtual systems on the same physical hardware (ala mainframe), however!
It might not be such a good idea to run critical applications off of those virtual machines, the reason being that they are all reliant on the hardware and OS underneath, should that hardware or host OS drop dead then you don't end up with one system down you end up with ten! Or twenty or thirty! (depending how many client OS's you install)
That said we use IBM hardware (funny that what with us being IBM an all :-) and they are REALLY nicely built and not your el-cheapo build it at home job PC, they are 4 CPU, 16Gb RAM, SAN backend and nicely engineered ... but they do still fail .. this week we had one of the gig-ethernet board die ... required an outage of the whole system to fix as the Linux host OS doesn't support hot swap PCI (yes I know the Linux now supports it, but the one IBM use is about Redhat 7 level .. which is a supported configuration so no changing it)
The moral of the whole VMware thing is ... Buy the best hardware you can if you are going to use it.
Regards