Consider the following Software Development Life Cycle diagram with which TDD, as well as any other software development methodology, I contend, can be used.
|Fig 1 - SDLC should accomodate any development methodology|
As you can see from the diagram above, there are distinct phases that have been defined. The actual design and coding of the software, if following this process, can be executed using any method chosen by the developers. What matters is that we get unit tested code ready for integration.
Your thoughts and comments are welcomed.