If Prescott can prove that he's improved on his reads, as well as his accuracy with downfield throws, then he can lead the team to the promise land. The biggest problem faced last season was when the team had to rely on his arm, when his first read wasn't open, he immediately went to the dump off guy for short yardage. His read progression stopped at his intended target. At least that's how I perceived it.
I hope for his success because that means the Cowboys are winning games and giving themselves a shot at the Superbowl. But if he cannot improve upon last years performance, I'd have to think they need to be looking closely at who they have, or can get, that can get the job done. And not just get it done for a season or two. Get it done for years to come (a.k.a. New England).