That is not necessarily true.
I know enough people (including myself) who have signed NDAs and are still
able to distribute the produced code in source form. You are just not
allowed to distribute the documentation, that's all.
> What do I have to worry about from the kernel and GNU camps?
> (ie. the driver would be a module dependent on kernel code, be compiled
> with GNU utilities, and not bound to any library).
Check the fineprint of the NDA. If it really does not allow you to
distribute the source, talk to them directly.
My experience is that the people who designed the NDAs never heared about
something like Free Software, GNU et al. You will have to explain the
concepts and advantages to them. Be patient but insistent and you are most
likely to succeed in getting an NDA tailored exactly to your needs.
They just want you to sign their standard NDA out of habit and because
they don't know any better (yet).
Mike