I often find myself grinding my teeth over TIMTOWTDI. I'm OK with it when the individual solutions are fairly orthogonal and tailored to a certain subset of the problem domain, and thus perhaps better suited to particular scenarios. However, for something as central to the software development process as unit testing, it strikes me as unfortunate to have a hodge podge of different solutions, many of them unofficial.
As a foil, I very much appreciate that Ruby has a single standard Test::Unit module that apparently everyone uses. It comes with the standard distribution, and it seems reasonably complete and well architected. It's sad that Perl does not have something similar. TIMTOWTDI is a double edged sword, the consequence of which is often that people end up speaking very different dialects of the same language, to the point that communication is stifled, or at least stilted.