I would be surprised if it happened, but it certainly would be a solution.
No matter how much ute fans hate to face the facts, BYU has a national following. BYU sells tix wherever it goes to local church members. Teams love to bring BYU in for a game. They could absolutely make a schedule in football.
BYU would absolutely have options to get tv exposure, regionally at least. BYU obviously wouldn't secure a contract like Notre Dame, but they could get most of the games on tv with much better penetration than the mtn, I would venture to bet. Revive the sports west network and get it on Gameplan.
The bcs has no bearing here. If BYU were ranked in the top 10 they'd get into a bcs game, guaranteed. Being independent would have no bearing. In fact, it would probably strenghten their resume, because the BCS loves to point out weak conference schedules as a flaw.
I doubt BYU would go independent in football, but if comcast thinks they might, they'll get this mtn thing worked out. If BYU leaves comcast's investment value in the channel goes close to zero.