A discussion worth checking out is this one on a CMS brand survey which amazon posted to the Drupal Group Marketing of Drupal. It references the following survey:
http://www.waterandstone.com/downloads/2008OpenSourceCMSMarketSurvey.pdf
I'm no marketing expert, but it seemed to me that while awards and other trends show Drupal surpassing most, Joomla were kicking our butts when it came to marketing and PR. However Amazon had a pretty good answer to that, though I think there is still much for Drupal to do on the marketing end, and this survey could be some help.
Overall it still looks healthy for Drupal, with Wordpress dominating, Joomla second, and Drupal third and everyone else a looong way off. It's interesting to note that technical proficiency is quite out of tune with marketing, with Drupal (possibly) under-performing, but doing vastly better than, for example, Plone, which has a lot of positives, but is lagging badly in this survey.
Grant