Wolfgang Ziegler (aka "fago") talks about the Rules module, and how it can be used by non-programmers to set up a series of events that are executed after certain conditional triggers happen. Fago claims that this is a more robust solution that Drupal's core trigger module functionality.

The Rules module in Drupal 6 is an evolution from the Workflow-NG module in Drupal 5, but renamed to reflect that it can do much more than just workflow.

There was also a Summer of Code project by klausi that integrated into the Rules package as the Rules Forms module.

Fago also talks about the future of Rules and how he plans on improving the APIs so that it's more extensible to add in loops and new features, and to have Features module integration with rules so that it's possible to and re-use rules.