Multiple versions installed simultaneously/multi-targeting

I considered posting this in the Feature Requests topic, but thought I'd try it out here, first, since it's sort of an edge-case.

I'd like to see the ability for multiple versions of Typemock to be installed on a box and running side-by-side. Not necessarily all at the same time, multi-threaded style, but something similar to the VS 2008 multi-targeting feature so I could have Typemock 4.0.0 and 4.1.0 installed on the same machine and say "build this and run against 4.0.0, but build that and run against 4.1.0." Maybe have an option in the little Typemock admin panel thing that lets me choose the "active Typemock version" or something.

It would make it far easier to take an upgrade - I could install the new version on my developer box and try things out to see if it all works (so I can recommend the upgrade be taken or troubleshoot if there's anything wrong) without having to uninstall or upgrade an existing installation.

The specific use case I have in mind: the latest beta. I have to think about how I'm going to try it out...

• Do I install on my developer machine or do I create a VM image to test this on?
• If I create a VM image, when, exactly, do I have time to do that?
• If I install on my developer box, I'm not building with the same tools as the rest of the group so before I commit, I really need to uninstall and reinstall the old version to make sure I didn't accidentally add a bunch of tests using features we don't have yet.