I'm pretty confident that Luck will declare, and he and Jake Locker form the top tier of the QB class. Mallett, Ponder, and Stanzi for the second tier but are late 1st Round - Early 2nd round talents. People may say that Mallett is in the first tier, but teams will be frightened by his lack of accuracy, character, lack of work ethic, and his "yo yo" eminem-on-stilts demeanor -- one website referred to him as a "retard with retard strength" (sorry if that offended anyone).
I think it comes down to who our coach is. If we have an offensive coach who is excellent with quarterbacks (e.g. Gruden, Brian Schottenheimer) we go with Locker. If we have a defensive-mided coach, we go with Luck.
That is because I feel that even though Luck is less experienced, he is more ready for a pro-style NFL offense and the NFL game. But if Locker gets decent coaching, he will be the next Steve Young.