An announcement of a partnership between the ACC, Big Ten, and Pac-12 may come on Tuesday, per Yahoo! Sports, though there probably won’t be much in the way of specifics on the mechanics of this thing.
The biggest longer-term implication is football scheduling, and this is one possible scenario moving forward:
An agreement where each football team in the three conferences would play one opponent from each of the other two leagues on an annual basis. In most cases, the opponents would rotate. This could help maximize revenue in upcoming television deals for the Big Ten and Pac-12, which have expiring media rights deals in upcoming seasons.