I think he's got a shot. I don't think it's a certainty or anything (his offensive game is still quite underdeveloped) but there is definitely a chance there for him to become a star in the league. Anywhere from a low level star (top ten SG) to a perennial All-Star caliber talent.
It's hard to put a ceiling on any player with as much explosive athleticism as Bradley. His physical talent gives him so many opportunities. Bradley doesn't really have a ceiling. If he keeps working hard, he can improve and improve and improve. There is just so much room for development.
I compared Bradley to Kirk Hinrich (when he was at his peak starting on the Bulls) earlier in the summer. More of a lower projection for Bradley but ... if Bradley only reaches that level (and no further), I'll be happy. I am comfortable expecting that from him. I think Bradley is very likely to achieve (at least) that. Anything more than that is just gravy.
And if Bradley starts to show more ability as a shot-creator, then the expectations crank up another level to a Joe Dumars or a Monta Ellis (with defense) type player.