We have recently gone through an exercise to provide a consistent set of prebuilt configured VMs for use in our TFS Lab Management environments.
This is not an insignificant piece of work as this post by Rik Hepworth discusses detailing all the IT pro work he had to do to create them. This is all before we even think about the work required to create deployment TFS builds and the like.
It is well worth a read if you are planning to provision a library of VM for Lab Management as it has some really useful tips and tricks