The only way to achieve this is to evolve to a Desktop as a Service.
Use something like newScale to build a Desktop Shopfront to connect your end-users to the desktop offerings, like Amazon does.
Develop a Desktop Factory on the back end with multiple production lines for each end-user solution (e.g. virtual pooled desktop).
These changes will separate the end-user solution from the actual technology to give yourself the options of swapping between XenDesktop and VMware View to suit your business.
We have many newScale customers who are doing this today.
They use our RequestCenter product to provide an IT storefront with all the proper options available to those roles. The catalog contains not just desktop images, but also access management - because it's no good to have a desktop you can't log on to.
Some customers also automate software distribution to those desktops.
The two key things that we see getting in the way are lack of standardization and lack of centralized process. These go hand in hand. If you don't have a set of standards, then the process is more like a bespoke model than an industrial one.