Amir Johnson was part of the last high school class to jump directly to the NBA. Although he's still not getting the playing time that guys like Monta Ellis, Andrew Bynum or even Andray Blatche are getting, Kevin Pelton of Basketball Prospectus still likes his future: "If anyone is likely to be the Jermaine O'Neal of this class, it's Johnson, like O'Neal stuck behind a veteran frontcourt for a contending team."
That's not to say Johnson will be an All-Star, but clearly he has the athleticism and skills to be a contributor at some point. The one question is whether he will be held back by his lack of playing time. O'Neal, it is safe to say, was not. Another interesting comparison might be another Detroit draft pick who had a tough time breaking into the lineup, Darko Milicic, who has proven a competent regular since getting his chance.