A nice article, and I think I should add the book to my (already too large) to-read pile.

I totally agree with "DRY might not be great in all cases" - In tests, it's often better to make each single test as expressive as possible. I once read (and forgot who said it):

"Code should be either DRY (don't repeat yourself) or WET (write expressive tests), but never damp)"

And here's a shameless plug: I recently wrote an article about how tests can help you achieve simple design, and the next article in the series will be coming soon: http://quickglance.at/en/simple_design/passes_its_tests