This morning's Halo 4 panel at PAX Prime was dispiritingly light on details. (Sample exchange: "How will the game play?" "It will play like Halo.") But the folks at 343 Industries did close out with a neat concept-art video, which I've posted above.
While specific details on the game were scarse, the panelists were clear that Halo 4 will dig deeper into the character of John (a.k.a. Master Chief). Art director Kenneth Scott said that the Master Chief seen in the teaser trailer would not be the final Chief in the game; they're on iteration number 4. "We know how important Chief is to fans. When people play Halo 4, we want them to have that feeling that "I'm a bioengineered super soldier wearing 800 pounds of tank and jet fighter."
Prompted by an audience question, Frank O'Connor confirmed that there were no plans to include a Halo 4 beta with disc purchases of the increasingly promising-looking Halo: Anniversary .