Well exactly that by the presenter, and Ed's reply was that you would be unlikely to finish a game in under an hour, but in under 2hrs. This as a design element to more suit multiplayer where 5 to 6 hr's being considered too long.
Some of this could be considered as just for multiplayer I suppose, however there was mention that it will be (can't remember the exact wording) higher in tempo gameplay.
Looking at the gameplay also suggest that. For a lot of things like building roads etc. it could be good thing though. Guess we'll just have to wait and see. I just hope the sense of achievement is not lost too much if things are too quick.