Quite honestly, this is a very old idea with new equipment. However, I don't know of anyone that has actually pulled it off and made a product of it. (the distributed computing part)
I left corporate IT nearly 10 years ago, and back then we had a combination of PCs and Citrix XenApp. And we were investigating distributed computing options of the time, as we were in a bank - batch processing is the perfect distributed computing
predecessor.
What it entailed was an investment in custom software and major changes in processing models.
If you have data chugging that you need done, consider BOINC and building a distributed processing project using its engine. That way you don't have to build the engine.
Pooling of resources across distributed PCs is actually rather difficult. Hadoop developed a storage layer specifically to handle this problem, and it still requires speed. Its model would work, but its requirements don't.
As far as 'thin clients' - they are thick clients since they are fully capable of local processing. This is where Citrix XenApp / XenDesktop fit as well as the corresponding MSFT Remote Desktop / RemoteFX solutions. (even that VMware company
and its VDI solution).
For Terminal Services - investigate XenApp / RemoteFX
For VDI - XenDesktop, MSFT VDI, and VMware View.
The architectures are similar for them all, the implementations and capabilities are different. As well as the situations where each shines.