This is already being mischaracterized as an agreement to expand, but it does sound like the ACC media deal spooked everyone and there's now a concrete move towards exploring and vetting options. The Big 12 school presidents voted unanimously to explore expansion options just today.
If you suspect ESPN is pulling the strings on some of this, I won't bet against you. They bought off Texas with the LHN to prevent a remaking of the college landscape and they aggressively secured the ACC network with a conference grant of rights that extends until 2036. That's a nice way of short circuiting future realignments or the prospect of a bidding war for TV rights for a national super-conference.
If you're an advocate of Texit (Texas Big 12 exit), this is probably discouraging news. Particularly given the fact the UT has a caretaker AD in men's athletics, and, like Deloss Dodds, he may not have the attention, interest or capacity to have Texas be a part of remaking the college athletics landscape. President Fenves appreciates the importance of college sports, but doesn't know much about them. And if his advisers are in Bellmont, their advice is going to be self-interested and centered around perpetuation of the status quo.
Caretakers don't plant olive trees.
An expansion of 2-4 additional members would all but guarantee a longer commitment to the conference with an aggressive grant of rights requirement. You'd also see a championship game (Dallas, JerryWorld) and a strong possibility of divisions.
BYU and Cincy are going to be the first candidates discussed. The next tier will be UConn, UCF, Houston, Memphis and Colorado State.
No word yet if Hofstra is available.