Converting Joomla to Drupal
Planning to make the switch from Joomla to Drupal? Now may be the time!
I was just reading over the New Modules feed when I spotted something called Joomla to Drupal. According to the feature list, it can import Joomla users, content, sections, and categories into Drupal.
Obviously, this project doesn't handle theme/module conversion, and I imagine there are some Joomla modules which would be incompatible with this type of export process. That said, for a basic Joomla to Drupal migration, this could be an invaluable time saver.
If you happen to give it a try, be sure to write up a review.