Well its obvious that a beta is looking to be out of the picture. And a multiplayer demo would be too farfetched for similar reasons.
And campaign? Well, the demo would lessen the impact for some who get to that point. Like the reach demo at e3 (using this as an example since the game demo was taken from the e3 demo) and judging from the campaign experience at e3, the demo would likely be too short and full of cinematics. And any other particular scenario just wouldnt fit.
We know we crash land on requiem and that we wake up on the FUD, but any gameplay of these scenes could ruin the experience for the retail game.
But what about spartan ops? for my example i want to be modest. So what about a demo for just two spartan ops missions? Each set with loadouts just like the e3 spartan ops/multiplayer demo. But to ease the idea of scaling a server for it, just make it solo.
A simple, single-player experience for those who wish to participate in the journey to halo 4 but are part of the majority who are unfortunately not able to go to particular events like e3, halo fest, rooster teeth’s event, etc.
So what about everyone else? Any ideas how a demo could work out?