If Bronco can continue to produce top 25 defenses (and there is nothing to suggest he won't) and Anae can get the offense back to being a top 25 offense (which is likely IMO), BYU will win enough and be successful enough even w/o going to a BCS game that the fanbase will stay more than interested.
Sure Reid and Saban are probably better X's and O's type coaches but could they (or would they even want to) handle BYU's mission and missionary program ?