By most people do you mean the relatively small amount of hard core fans on these forums? Because you know, only a tiny tiny tiny fraction of the people who will end up playing Skyrim will ever visit this forum right? And those that do will be the more hardcoe fans (the ones who don't want to spoil the game for some odd reason)... and not representative of the casual users that Bethesda actually wants to sell the game to. Oh, and thats not even counting the people who might be on the fence about buying the game and could be swayed with a good demo. So really... you have absolutely no idea how much desire there is for a demo among those who will/might buy Skyrim. I can tell you this thought: If there was a demo released, it would be an extremly popular download.

With that said I don't like the OPs idea and feel it would be too much work for a demo.