Here is a useful article comparing Drupal with WordPress, and a few other content management systems as well. It is a more in-depth companion to my article comparing Drupal and WordPress. The chart comparing CMS systems outlines about what I found in my own research. For example, WordPress is easy to install, but is less scalable. Drupal is harder to install, but provides more control and more features. Then there is Typo3 - many features but very hard to set up.