There is an interesting discussion going on at the Agile Software Testing Yahoo group around the benefits of virtualizing your test lab.
One of our customers who loves our guest automation capabilities (see a demo of this capability) has responded and added his thoughts to the thread. Here is what our customer had to say (bold mine):
> For test labs, if you have some technical people, you can actually put
> together automated lab solutions where, with the ‘press of a button’ you can
> deploy mutli-box topologies with automated configuration behind it.
> Depending on the time to deploy (mostly the complexity of the environment
> and the post-deploy configuration, including data population) you could tie
> this into your CI solution and run unit tests/bvts on a clean environment
> (which may–or may NOT–be useful to you).We’ve implemented this at Atlassian by integrating VMLogix’s LabManager
(http://www.vmlogix.com/Products/VMLogix-LabManager/) with our own Bamboo CI
server.
One of the great features of VMLogix’s product (and I say this as a paying
customer) is it’s ability to automate the installation and configuration of
software on virtual machines. This means we don’t have to manually configure
VMs. If a CI build needs to run on a certain platform (o/s, jdk, app server,
database, browser, etc.) and no VM image already exists that matches these
requirements, Lab Manager will create one as part of the build (and save it for
later use if desired).
We use this feature to also install a remote agent for our CI server on the
VM(s) once they’re deployed. This remote agent is what triggers and monitors the
build and passes artifacts like test results back to the CI server. When the
build finishes, Bamboo instructs LabManager to undeploy the VM(s), freeing up
resources for other builds.
This infrastructure benefits manual testing as well, because testers can not
only deploy, but also design custom VM environments in minutes via LabManager’s
web interface.
If you’d like to try out VMLogix LabManager yourself, download the free trial version from here.
Posted by vmlogix 
Virtual Lab Automation Blog 