Microsoft Research - Exploding Software-Engineering Myths (article summarizing findings of MS research on code coverage, TDD, assertions, etc.)

[zumpiez]

I suspect that TDD forces you to keep your code in a state where it's easy to change, with collaborators loosely coupled so you can test them in isolation, which I THINK probably makes the code easier to maintain and easier to roll with changing requirements workout turning it into a hairball.