Hi,
I don't think ASP.net applications are a target for running on a Windows HPC Server 2008 R2. The cluster we talk about in this scenario is a bunch of machines working together to solve a common problem. Your ASP.Net scenario most likely does
not need to run into a distributed environment.
If you are looking into having your application scale out, then I'd recommend hosting it in Windows Azure.
Cheers,
-Christian