I confess I'm a little puzzled by all this; why would someone use this? You pretty much need to have such a computer already to use it, so what does it get you?
Working from home - Perhaps you or your employees home machine is a Mac. An alternative is poking a hole in your office internal network to RDP to your PC.
Conserving office energy - Have workers shut off their office PCs at night.
Upgrade path - Perhaps your company has older PCs running XP. This is one option to an upgrade path to Windows 7 and future versions of Windows.
Easy deployment - Perhaps you work in an environment with lots of employee growth. Get them up and running fast.
Thin terminals - Have a less powerful, bare bones machine for access to your Remote Desktop. Imagine employees running off of devices like a raspberry pi.
Terminal stations - Work from different desks in a larger complex.
Licensing - This can be a cheaper or preferably month to month option for people wanting to run Office but not wanting to pay the full up front cost.
Testing - Perhaps your office has Mac desktops and you need a Windows PC your company can share.
That should get you started :)
I would also add that thin clients and schools/college/university would be a great use case.