I somewhat disagree with Jon on this point from The art and science of software testing
When up to half of the output of a full-blown TDD-style project can be test code, we're going to want to find ways to automate and streamline the effort.
If you discipline yourself to write the test first, then any it-would-be-cool feature becomes immediately twice as expensive. As a lazy programmer I don't want to put the effort into writing a test for some speculative flexibility until the customer actually asks for a feature requiring it. The time-cost of writing tests creates natural resistance to unnecessary bloat. With that in mind, I would be cautious about streamlining the testing effort. Too much streamlining will take away this really excellent side-effect of testing first.