I like the idea of importing through laser scans, it would kill 3D modeling and add real-life scenery. You'd put up some hollywood-like-ish scene, scan it and boom! Can you imagine?
Yeah, I think if you were doing a game that has any kind of roots in reality, it would be vastly easier to make all of your props. Dunno about sets, as the cost might outweigh just generating one. Maybe they would scan scale models?
Just think about this though - how many times do you think mundane items have been remade for games over the years? Coffee cups, bottles, toilets, etc? If that takes off, some smart individual should probably make some kind of common geometry library, like they do with sound libraries. There would be no polygon limits so you wouldn't have to worry about them working within the limits of different games, right?