I think we are drawing to a close on our blog forum, and I think Jeffrey and Bill have graciously agreed to let me have the last word. I greatly appreciate all the points and comments, and am (naturally) particularly fond of Bill's robust defense of teaching evaluations.
As for the question of the complexity of the relationship I am actually planning to use the underlying data for two additional projects that may reach some of Jeffrey's concerns. The first is a large scale regression analysis where I greatly increase the number of variables to include any publicly available AALS information on the law professors studied (such as gender, years in teaching, years in practice before teaching, law school attended, primary teaching area, etc.) to see if any of those variables correlate with teaching or research.
The second is a qualitative study of the professors. I will start with a mailing inquiring about their own views on the interaction between teaching and research, and then probably follow up with some phone interviews. With these additional data and observations I will hopefully be able to offer more than just the raw numbers. Thanks again for the forum, and please don't hesitate to email any further feedback or suggestions. Ben Barton.