VMLogix has been talking about linked clones on their corporate blog for a while now.  In the latest blog post, they write:

There is little doubt and debate over the tremendous benefit of using linked clones in a lab environment (where the rate of change is high, the collaboration between users is high and many users access the shared lab infrastructure).

In an environment where there is a high degree of flux, and linked clones are used abundantly it is difficult for IT administrators and lab users to keep track of the “linked clones tree”. I.e., what are the dependencies between the various VMs? Which VMs are parents - which ones are children etc.

And in a new release that will be coming out shortly by VMLogix, the company's LabManager product will be adding a visual ability for users and admins to actually view the linked clone tree and its dependencies.   

And here is a brief movie that demonstrates this functionality.