Nothing is going to happen with conference realignment until the selection process for the playoff is determined. If the SEC gets it's way and can have more than 1 team in the playoff, you can probably expect to continue to see conference movement. If not, and it is determined you must win your conference to be eligible (my preference), then you will probably see the movement of teams out of conferences slow down quite a bit. There would be no advantage for a team like Clemson or FSU or VT to leave a weak ACC for a stronger conference.
The potential catch here is with schools like ND and BYU. If it is decided that you have to win a conference to be eligible for selection, how does ND and BYU get included presently? These are the types of things that have to be determined. I personally don't see ND going to a conference for football as long as they have the ability to have access to a National Title without a conference and they still can pull in the amount of money through NBC that they currently do. There really is no advantage for ND going to a conference at this point for football. That, of course, is subject to change based on TV and what happens with this playoff situation.
As for ND going to the Big 12 for their non-football sports, I'll believe it when I see it. There is a lot of posturing going on right now and the Big 12 is trying to lure ND football any way they can. If the Big 12 realizes that ND is not coming for football, I think this dies and dies pretty fast. If they still think they can lure ND for football, this will continue to pop up from time to time in the media.
This whole thing will come back to haunt the non SEC power conferences and Notre Dame when year after year 2 SEC teams will capture 2 of the 4 playoff spots. Another probably going to the Big 12 Champ with the Big 10, Pac 12, and ACC fighting to place one team in the final spot.