Update - 22 Feb 2010:
One of the issues lightly touched on below is the market need for some themes besides those on drupal.org. Acquia has started to collect both themes, as well as links to theme providers, at a new site devoted to the design-aspects of Drupal. See design.acquia.com
for more information.
(Original post follows.)
For almost as long as I've been involved with Drupal, there's been a running complaint – either a (false) perception or (true) reality – that Drupal is "theme-challenged" compared to alternatives like... More