Unit testing kernel drivers
Being the author of cfix, I might be a little biased here -- but as a matter of fact, I am currently not aware of any other unit-testing framework for NT kernel mode.
If you should experience any problems with cfix, feel free to contact me.
Microsoft Static Driver Verifier is described as "a compile-time tool that explores code paths in a device driver by symbolically executing the source code. SDV is a unit-testing tool for Microsoft Windows device drivers based on the Windows Driver Model (WDM)."
Is that what you're looking for?