That sucks. I wonder why? It seems to be the part people walked away most impressed with. If it's got such great buzz, why not show a couple screenshots even?
I thing they ought to release 60fps direct feed videos only. Shows one of the strengths of the game (framerate) and the awesome animation system.
Hopefully there WON'T be any DOOM stuff at QuakeCon, id needs to learn to show stuff for the first time within the year they're releasing the game.