The Drupal for Facebook project is certainly open, and eagerly encourages contributions. Those familiar with the Drupal world already know how to do it: download the code, run it yourself, improve it and post your patches back to the project.
And just to clear up some terminology, it's not really a matter of "porting" http://www.drupalforfacebook.org to facebook (http://apps.facebook.com/drupalforfacebook). Rather, all the content exists on the www.drupalforfacebook.org server, and the content is also displayed on facebook via the facbook api canvas pages. So you could add or edit the content via either URL, and the changes will be shown on both sites.
The goal is not to create one singe drupalforfacebook application. The idea is to make Drupal, which is already a great way to develop an online application, into a great way to develop a Facebook application. So you will be seeing more and more facebook app that are "powered by Drupal for Facebook."