I think in an optimistic scenario (assuming a healthy Carmelo + Amare), we could see Shumpert averaging:
34mpg, 16ppg, 5apg, 4.5rpg, 2+spg, 45%fg, 37%3pt.
I don't think those #s would be good enough to win ROY this season. I can picture Irving and Rubio putting in some sick numbers. Irving already has the green light to do whatever he wants and doesn't have any bonafide scorers on the team - meaning he could/should be pushing 18ppg+, leading the team in assists, and picking up a lot of rebounds.
Rubio has some impressive assist numbers in the short term, with pretty nice shooting numbers and rebound numbers. Statistically he's Jose Calderon with steals. He might become Jason Kidd with more refined shooting or better shot selection!
Beyond those 3:
I'm not really clear on what Brandon Knight is - he's also been handed the starting keys at guard, giving him high scoring/assist potential, particularly with the established (and currently back with his shooting mojo) Ben Gordon with him in the backcourt.
With DJ Augustin putting up career numbers at PG on Charlotte, I don't know if Kemba Walker will have the opportunity to learn on the job as a PG. This year at least he'll have to deal with limited minutes overall, unless Gerald Henderson goes down, forcing them to start a super small backcourt - giving them a little bit of the Golden State Warriors east (Curry/Ellis) flavor, except smaller. Kemba's had some great stretches, but I have doubts he'll be able to fulfill his Tim Hardaway-like destiny, not this year anyway.