I used to have a wordpress blog at Ghent University, but since acquiring the itkovian.net domain, I decided to move to drupal. However, every tool I found to port my posts over was targetting drupal < 5.0.
A darcs repository is available for a Python script that takes out posts from a wordpress database and injects them into drupal. The code is licensed under the GPL-2, so feel free to extend it.
At the moment this script will only transfer posts, without comments. To transfer the wordpress categories, it requires a free tagging vocabulary, and you need to know its ID in your drupal install (you can find this at ‘admin/content/taxonomy’ and selecting list terms for the chosen vocabulary). It also requires a minor patch to the drupal blogapi module, to allow the wordpress post dates to be taken along. You need a configuration file with a [wordpress] and [drupal] section, detailing the hostname, database, login info, etc. Example configuration files are provided.
You can get the required files by
darcs get http://itkovian.net/darcs/wordpress2drupal
If you choose to extend the code, you can email the darcs patches to itkovian drats gmail drots com.