Although the cases are few and far between, there is an interesting use for nonpersistent VDI, and it comes from requiring fewer Windows applications.
A few weeks ago I wrote about how the fewer Windows apps you need in your organization, the more nonpersistent VDI makes sense. I've also talked at length about how the future of Windows is that of middleware, meaning desktop admins aren't running Windows because they want to, but rather because they have to in order to use a specific application. In this world where Windows is middleware, I expect Remote Desktop Session Host (RDSH) environments to experience a bit of a renaissance because you can put all the one-off apps that users need into RDSH farms and just deliver them as necessary.
I'd like to take that thinking a step further. If you have so few Windows apps that you sequester them away on RDSH servers, that would also fall into the same discussion surrounding nonpersistent VDI and fewer Windows apps. Technology has changed such that we are now achieving RDSH-like user density on VDI hosts of similar hardware.
So, what if instead of deploying apps to RDSH servers, you deployed them to nonpersistent virtual desktops that are stood up only for the sake of running a single application, but then were destroyed when the user logged off?
Why nonpersistent VDI over RDSH for apps?
It's a compelling use case for apps particularly because deploying applications to RDSH hasn't exactly gotten easier over time. There are still compatibility concerns and the dreaded, "What's a terminal server?" question coming from the software vendors themselves (it still happens, unfortunately). This deployment also requires a more advanced skill set than simply managing Windows 7, not to mention a slightly different user interface.
More on nonpersistent VDI
How persistence affects security
Shared vs. personal disks: Which require more resources?
So, even if it's a little more expensive to deploy apps on nonpersistent VDI desktops, doing VDI instead of RDSH could be worth it for some administrators looking to manage and deliver a more familiar Windows end-user computing scenario.
Again, if you're still running mostly Windows and mostly Windows apps, nonpersistent VDI might not be the solution for you -- right now. But as we move toward fewer Windows applications and more common on-premises, browser-based apps or cloud apps, it becomes more compelling.
With regards to licensing, it only works if you've already paid for VDI. If you haven't, then why go through the expense? In fact, until Microsoft fixes VDA licensing, there's a more compelling financial case to do the exact opposite: run Windows 2008 as a single-user RDSH server for your VDI virtual machines. Here we are in a situation where the most technologically appropriate method winds up taking a back seat to the cheaper one that's not quite as good. We pick on Microsoft so often you'd think it was fun, but it's mostly just frustrating.
Moore's law, advanced VDI platforms and modern hypervisors have made it possible for desktop admins to make their lives easier when it comes to managing Windows apps, even as the spotlight on Windows apps fades. As you start either allowing non-Windows endpoints or choosing not to manage them in favor of securing the access to apps and desktops, it starts to look more and more appropriate to deploy singular apps to nonpersistent desktops. Plus, it's another use case for nonpersistent VDI.