Hats off to Cem Kaner
I've read his article, Architectures of Test Automation [http://www.kaner.com/testarch.html]. I've seen many of these considerations come up in practice, but it's great to have them formalized, or at least written down.
More good stuff available at http://www.kaner.com/articles.html. And remember, test automation is software development, so there's no reason to go about your business any differently!
