According to John Arguello's "Cubs Den" blog, Hoyer scouted Prior-esque (at least in his physique) USF righty Kyle Zimmer:
http://www.chicagonow.com/cubs-den/2012/03/draft-preview-cubs-scouting-rhp-kyle-zimmer/
OK, I watched a couple YouTube videos of Zimmer just now and I don't love his mechanics. He doesn't seem to have the recoil that Mark Prior and Mike Harkey had (and that's a good thing) but he does seem to throw across his body a tad (and that's a bad thing).
It looks like he's got the dreaded "M" (I'm trying to start a trend that phases out "inverted W" because that sounds dumb to me) that a lot of people believe eventually leads to shoulder surgery.
Finally, he pats the ball in his glove a la Geremi Gonzalez, which doesn't mean anything, really. It's probably a timing thing he's developed along the way.
Obviously, throwing across his body could be an easy fix, if he's coachable. The "M" could be a problem, if you subscribe to that theory.
He's certainly a big kid who seems to have good stuff.