I was about to mention this. I didn't follow Duke basketball (or even much college basketball) before 1980. But while Duke was successful prior to then, I don't think there was also such a "lasting legacy" back then, either. With the current Duke basketball legacy and culture, I would think the first successor to Coach K will be from within... if only to keep some kind of initial continuity. Maybe a few years after that, who knows...
And, with all of the names thrown about, I thought, well, in 5-10 years, where will Greg Paulus be?
He'd be young enough (very early 30's) at least, and who knows where he'll go or how he'll grow in that time.