The only AAU members up for grabs are:
-Duke
-Georgia Tech
-UNC
-Pittsburgh
-UVA
If they want to get up to 16 members to keep up with the other conferences while only including AAU schools, they're going to have a tough time of it. Duke, GT, and UNC would much rather be in the SEC, I'm sure. That leaves them with Pitt and UVA for 14 members, so eventually if this "super conference" thing does happen they're going to have to bite the bullet and consider schools with a "x-year AAU membership" plan.
Edit to say that the B1G also already has one non-AAU member in their conference: Nebraska.
Yes, but from what I understand Nebraska was booted out of the AAU after they joined the Big 10. It did make a difference in their entry.