vVirtualisation is already gaining momentum on the server and will become common on the Desktop as well.There is Xen virtualisation which is an open source virtualisation technology which is gaining a lot of momentum and then there are virtualisation management tools to manage all the virtual machines.
Xen is open source virtualisation and has excellent performance because of para virtualisation. Its also at a lower costs and requires some services to be setup. If a customer is saving money by using Xen, they would be willing to pay for services.
There are ways to secure virtual machines just like you can secure a physical machine. One of the technology is AppArmor which creates a firewall around applications. With AppArmor you can secure the virtual machine.