What? They aren't "true" in this demo and the new ign gameplay vid?
No there will be an option in the game for tru iron sights, iron sights with crosshair, and just a zoom with crosshair.
True iron sights: aiming down sights
iron sights: Aiming down sights + the little blip to show you wear to aim
zoom: FO3's aiming where you just zoom in and use the little blip.
there might also be an option to just zoom without the little blip(crosshair).