The gamble ESPN would be taking is that they'd be counting on CFB fans to be interested in a small semi-pro league. I think much of the appeal of college football (and the network$$$-fueled conference re-alignment has been slowly destroying it) is the school pride, rivalries, traditions, etc. Will fans tune into a league of a few elite core teams and continue watching? We have pro football for that. I am not going to tune into watch the Big-10/SEC championship league and pick a team to be loyal to. The gators? Forget it.
My hope is they screw it up so bad, that it backfires on them, and we eventually end up with regional conferences again.