> on the same big pile of hardware.  It becomes enormously cost-effective
> when you ramp the numbers up a bit....
> 
> Think about scenarios like web server farms for private hosting -- you
> give the customer the root password and let him play all he wants!

and take $20 for every reinstalation when he get system unusable ;)
then you can easily make a fortune :)
 
> However without an underlying "hardware management system" like IBM's VM
> operating system on which to host logical virtual systems, it's almost
> impossible to manage such powerful hardware effectively for any truly
> general purpose multi-user computing environment.

depends of needs. but in case you described - yes.