Did you know that it is already possible to write .NET plug-ins for 3ds Max? One sample that demonstrates this is the Scene Explorer sample. Theis sample combines managed and unmanaged C++ into a single DLL, and uses an assembly (i.e. a class library) exposed to .NET that is documented in the SDK documentation.

One problem with this approach is that mixing managed and unmanaged code can be a bit tricky. You have to write a lot of wrapper classes to share data back and forth between code that is managed and code that is unmanaged.

What I want to know is how many people would be interested in writing plug-ins entirely in C# or another .NET language?

While even simple "yes" or "no" posts will make me happy, I would be especially interested in hearing your rationale, and whether such a feature might influence a purchasing decision.