Disclaimer: I'm one of the authors of Two Scoops of Django.

This screencast looks awesome! Okay, now to your questions:

First, the screencast for creating a HN/Reddit clone is a tutorial. It's a good place to start when developing in Django, or as a reinforcement for the existing tutorial.

Second, Two Scoops of Django came out first because we (me and Audrey Roy) wrote it first. Arun Ravindran, who is making this tutorial, is a separate person and completely unaffiliated with us.