Coaching hires are crap shoots most of the time. Occassionally, you get some WTF hires. Honestly, Embree and Kiffin both filled that bill. Pete Carroll was a WTF hire that worked out.
I put the Petersen hire in the same category as HCMM. Jury is still out. While Petersen has won, a whole lot, he's done it at one school in a lesser conference - mostly in the WAC. There are loads of failed coaches with similar pedigrees that couldn't make the jump. HaLk is a prime example. He may turn out to be the next Jim Tressel, who jumped from Youngstown State to Ohio State, and won at both places. The length of Boise State's run suggests that Petersen is more likely to be successful than not, but who knows?
IMO, the only sure fire guys are the ones who have won at multiple stops - Saban at Michigan State, LSU and Alabama, Les Miles at Oklahoma State and LSU, Urban Meyer at Utah, Florida and Ohio State.