I think TDD is over hyped, it is something many people seem to treat as a silver bullet. That being said I’m not sure if it is fair to say it is fundamentally wrong. As with many “silver bullets” it has its place, I’ve found it particularly useful when I’m writing a complicated function, it forced me to focus on inputs and expected outputs and I code to that specification. With regards to a changing specification, that is a problem regardless of when or who writes the tests, it is a part of life regardless.