@Crimsonorblue22 asks a fair question of how much Big Dave improves. I think he will be improved because he is a hard worker. The question is not if he improves, or even how much, but where.
If Dave improves as a scorer, that helps some, because Self will always want to be able to throw the ball into the post, but because Dave isn't a superstar scorer, unless he improves to that level, too much improvement here could be a detriment because it may lead KU to trying to run its offense through Big Dave rather than keeping things on the perimeter, where there are better scorers. So if Dave isn't a superstar scorer, KU is better off with him more or less being the same, because him getting more touches may not improve the team long term.
Now, if Big Dave has improved as a passer, we are talking about some major team improvement here because now we are talking about him kicking the ball out from the post to a bevy of capable shooters. While a modest improvement in scoring doesn't necessarily help KU next year, a modest improvement as a passer does because that unlocks parts of the offense that currently are not open.
In the same vein, a modest improvement as a rebounder helps KU because it means Big Dave can more ably be relied on as the sole big man in the lineup without KU getting smashed on the boards. This is also an area where Dave has a chance to really improve, so improvements here would be noticeable from him to even the most casual fan, and it would make a big difference for the team as well.
If Big Dave improves defensively, particularly with rim protection, this is where KU probably improves the most. He isn't bad defensively now, but if he improves into a true deterrent around the rim, that helps KU's otherwise pedestrian perimeter defense move closer to a championship quality group. KU has a chance to be improved on the perimeter defensively next year as a unit (having one or two top notch defenders doesn't help if other guys are below average). If that happens and Dave can anchor the defense in the middle, again, that allows for a noticeable improvement, raising both the floor and the ceiling for this team.