create dynamic group for virtual and physical machines

I have been doing research on how to best create a dynamic groups for virtual and physical machines. I found the virtual machine attribute but it seems like it only gets set for Hyper-V and not for vmware. Anybody have an easy solution to populate a group with vmware machines.

We have registry keys set for various attributes then use discoveries to add them into a class which you can then use to populate a group. The regkeys are embedded into the server build process.

I think this oldy from Kevin Holman is still valid