The various characters discuss the themes of the season, which seem to simply be amplifications of the themes of every season: Jesse’s in a dark, sad place; Walt becomes almost 100% criminal, Skyler develops a taste for the lifestyle.
Essentially, all this featurette really does is remind us of two things: all the different trajectories that were established over the first 3 seasons, and how well Breaking Bad tells those stories.
It doesn’t take much to get fans of the show excited for the new season. How do I know? Because these featurette gives us virtually nothing but a great reminder, and I’m excited.