I feel like Petty has terrific physical attributes for the NFL and the transition for him is all mental.
Can he learn a complex NFL offense, the multiple checks, reads, audibles and all the rest of it, which is light years away from what he was doing at Baylor, and can he learn to read complex NFL defenses, but to a degree this is true for all college QB's transitioning to the NFL, it will be true for Winston and Mariota as well, its just more true for Petty because the system at Baylor is pretty simple. Its like going straight from fundamental mathematics to advanced calculus.
Its gonna take time and WE FANS won't know for sure if he is THE GUY until 2016 at the minimum, don't even think about seeing him on the field in 2015 once the preseason ends, BUT THE COACHES WILL HAVE A MUCH BETTER IDEA and thats the important part. By the end of this year they will have a pretty good idea if Petty is picking up the system and making genuine progress towards being at least a quality starter in this league.
So to answer your question, we may not know at the end of this year if QB is still our most pressing need, but Mac & Bowles will know, or at least they will have a pretty good idea, and that will determine if we target a QB in RD 1 (Jones, Hack or Cook) or a much needed OFFENSIVE TACKLE, and then draft another QB after RD 1 just to be on the safe side, just in case Petty doesn't workout.