Lets see. You missed out that in the last two games the Player Characters had battle grunts.
I don't know exactly how the shouts will impose a personality.
Unless, of course, its said like this: "Like, FUS RO DAH, or whatever".
The battle grunts were hardly noticeable.
The shout in the Skyrim trailer is bad enough at imposing a personality, and unless i'm mistaken that's one of the shortest shouts there is.
Obviously it's noowhere near as bad as a fully voice-acted player-character for imposing personality - but it's still a big step in the wrong direction. I just hope Bethesda don't go any further down that road.