The growth of Drupal themes will directly mirror the growth of custom distributions. We are currently in the “it’s so easy, we click together lots of Drupal modules from scratch” phase. Once there are more Open Atrium and ProsePoint type of distributions, with known modules / module options and features, then you can build great themes to support those functions.
Form follows function. I’ve tried to explain this a million times in the D7 process. Having a “great” core theme is impossible when we don’t decide what kind of site Drupal should be optimized for out of the box. This same holds true for trying to build and market a theme that will apply and work well with the many vastly different kind of sites that one can build with Drupal.
Yes, CVS is “hard”. Yes, all GPL is “hard”. I would argue that the overhead of trying to create infinitely flexible themes for any possible view, module, and block layout is the hardest part. Define your functions, and we’ll have the beautifully formed themes to match.