Florida v Georgia is probably a bigger game for Florida than FSU.
OU and Nebraska used to have a huge rivalry. Over the years it has changed to OU and Texas. Now Nebraska and OU will not play anymore. And no one will really care.
BYU is very geographically isolated to have a natural rival in the B-12... but like with the MWC... BYU fans will find they want to beat OU and Texas pretty bad every year... They will be the class of the conference.