The panel starts at 10am PST/1pm EST. IGN will have a livestream of the event right here.

From IGN:

Up Next: Halo 4
10:00am-11:00am PST
Here is your first chance to see and hear from the 343 Industries team that is creating the exciting next chapter in Master Chief's heroic story. Panelists include Franchise Development Director Frank O'Connor, Creative Director Josh Holmes, Executive Producer Kiki Wolfkill, Senior Art Director Kenneth Scott, and Audio Director Sotaro Tojima.

A lot of talking about not very much. I'm excited for this game, but having a panel for it now seemed premature. The questions section was particularly pointless, as half the time you knew that they were going to give a fat "we can't answer that" before the person even finished asking.

Eh, it was an alright panel I suppose..Though I'm not very excited for the game.

I think the "biggest" thing to come out of them dancing around revealing pretty much anything was the fact that the story for the Arbiter and the humans post-war will continue in this trilogy. Interdasting...