Dak's got the mental side of QB'ing on lock. I have been seriously impressed with his decision making the past 2 seasons, in how well he balances risk with aggression. And he throws with anticipation, which is frankly something I never thought he would figure out. At this point, he operates the offense like a QB coach on the field.
Now it's just a question of how long his arm holds up. His legs are shot at this point - even if he has any juice to run, he won't b/c of the injury risk. His arm hasn't really declined, but it was never better than NFL average to begin with, so he doesn't have much to lose before he dips under the Chad Pennington line. So long as his arm stays above pop-gun level, he'll remain a top 10 QB just on smarts alone.