The goal of the Drupal Ladder initiative is to get 1% of active users on drupal.org to contribute to Drupal core by 2014 by organizing "learn sprints" and "issue sprints" at Drupal User Group meetups, camps and conferences.
"Drupal Ladder" is the new name for this initiative. It had previously been called "Learn Drupal," but this led to a lot of confusion: many people assumed that the goal was to help new users learn how to use Drupal, though the goal is actually to get more users to contribute to Drupal.
The new name better conveys this goal by referring to the Drupal Contribution Ladder, without being specific to it. In the future, this initiative (and the website) may well shift focus, but the paradigm of climbing a ladder of lessons will remain.
We encourage Drupal community members at all levels to become involved in the initiative—there's something for everyone to do! Take part in the group discussions, join us in IRC at #drupal-ladder, or help build the Drupal Ladder installation profile by helping out in the issue queue. The best way to get involved is to take part in learn and issue sprints. If none are happening in your local user group, plan one! The Drupal Ladder site includes information on planning and running sprints.