There is a very good article over at the Zend Developer Zone about the recent DrupalCon.

We do a lot of work with Drupal, especially with the good folks at Evolve Strategies. It has grown and improved considerably since we started working with it around version 4.

I have been developing PHP since the transition from version 3 to 4. As the language has matured so have the great technologies it powers. Drupal is one of the applications that gets better with each version.

The ZDZ article is very good and recommended reading.