Obviously comparisons to Timmy D are unfair for us to pin on any frosh. HOWEVER, for someone who was a sophomore in '94 and got to see every one of Tim's games up close and personal, it's not a stretch to say that Tim Duncan was a DREADFUL offensive player as a freshman. He was all defense, rebounding and shot-blocking. So many times, he had no clue what to do with the ball on the offensive end of the floor early in his freshman campaign. He used to travel a lot and had difficulty pivoting to his strong hand.
At that point in time, he seemed like a project with some potential to become a serviceable offensive player and a routine 10/10/3 guy. I don't think anyone saw him becoming one of the best ACC players of all time. But then he worked his tail off before his sophomore year and became a completely different player. That kind of progression is unheard of in sports for someone who barely played the game growing up. It is a remarkable feat that Tim Duncan transformed himself into not only one of the best college players of all time, but perhaps one of the best 3 power forwards to ever lace 'em up in the NBA.
As for Devin, assuming he can avoid a devastating injury, and he continues to work on his footwork and quickness (albeit big man quickness), I think the sky's the limit for him. Plus, we don't even know if he's done growing yet, n'est-ce pas?