He's a very good role player that would be better served coming off the bench. You can't build a team around him, so I wouldn't say he has star potential. Dollar for dollar, he's one of the most underrated players in the league.
He's a shooter, he won't become a go-to-guy, a guy who can create shots for himself. Never, that's a different profile. His ceiling is whatever... as a shooter. Now think about different shooters: Ray Allen, Rip Hamilton, Mike Dunleavy, Stojakovic... He has potential to score a lot, and efficiently, not necessarily creating his own shots. But if he wants to have the necessary playing time to do that on a winning team, he must improve his overall intensity and defensive level. He's still very young (23), who knows... could happen.
Budinger is at his best coming off screens, but will probably never hit shots at a Rip Hamilton or Ray Allen level. Part of their game is their above average handles and the threat of getting to the rim, which Bud doesn't quite have. He'll still be damn annoying to other teams, though. My brother is a Laker fan, and speaks of Budinger the same way I speak of Korver. Guys like them drive you nuts because you just cannot give them an inch of space, but they are often left open.