I wasn't sure if I should comment on this, but the power of Agile and good programming compel me. I love TestDrive.Net. I've shown it to my group on more than one occasion and will tell anyone who will listen about it. Yes, the next version of Visual Studio is greatly improving the test-first experience, but in the meantime this is without a doubt one of the best tools you can buy for coding.
I can't argue that Jamie is in the right - he's definitely not. The EULA for VS Express clearly states that you cannot write extensions for the free version of the application. At the same time, I believe test-first development is crucial to learning to be a good programmer, and depriving hobbyists of this wonderful extension is cruel at best. I don't know what the solution is, and I'm definitely not a lawyer, but I really hope everyone can come to an amicable end to this situation.