All you dummies whining for a demo realise that the quality of the final product WILL suffer because of the time invested in producing the demo, right?
Software development is a hideously complex process, especially for games of the scale and scope of something like Fallout 3. Saying that all they have to do is "section off part of the world and write a few fun quests" is goddamn retarded. That's weeks upon weeks of design, development and testing work that could have been better used fixing bugs with the main product.
Get a damn clue before going off on these stupid rants.