This is another article that helps you understand when VDI might be a good choice for you and when TS might be the best choice. The key is to have the flexibility to host both of them effectively.
With all of the momentum behind VDI deployments, organizations are beginning to realize that with the advantages come some unexpected costs and complexity. One of the biggest challenges is managing VDI deployments. In theory they should be easier to manage than legacy physical desktops, but the management tools for physical desktops are very mature, well understood, and in many cases, already in place.
An unexpected side effect of this realization is that many organizations are re-evaluating whether Terminal Services (TS) might be a better fit for them than VDI. As Brian Madden has said for years, it really comes down to understanding specific use cases.
Here are some questions to answer to help you understand your use cases and whether TS or VDI is an option over physical systems: