The PP and Len Bias comparisons are off the mark. Young has nothing like the skill that PP was already showing at the time, nor the athleticism of Bias. I hope that he, like PP, will exceed expectations; but many, many other guys have exceeded expectations, too.
Young is an upside pick with a wide range of outcomes, but none of them resemble Paul Pierce. To me, his dream outcome is more like a slightly less productive Ray, a phenomenal shooter who can also do everything else. However, there's no reason at this point to be so optimistic; he was very good but not exceptional from 3 for Duke, and he won't match Ray's ability to get just barely open and pull the trigger before his man gets to him. Question marks include his right hand and his defensive acumen. If he puts the latter question mark to rest, I'll be enthusiastic about the kid-- but I still won't be holding my breath for him to make an all-star appearance.