I have been mentioning this analogy verbally to folks for some time and found it is getting good traction, so time to write it down in pixels.
The browser was initially not free and had a lot of hoopla around it, hence the rise of Netscape. Soon the browser became free since folks realized that the value is not the browser it self, but rather what you can do with the browser, the rest is history.
There is a similar trend happening with VMs, they are currently costly (at least the high performance ones like ESX from VMware), but soon the VM will be free. The true value will not be the VMM it self (i.e. the hypervisor), but in what it enables. VMware is obviously aware of that, hence why all the value-added applications they are building (like VI), and their acquisition strategy (B-Hive, Determina, Foedus, Thinstall, Propero, Akimbi, Dunes, etc)