I had read elsewhere that Rutgers was getting serious consideration. They're fielding some top level teams, and they capture the NYC market since they're only about 40mi away from the city.
What about Cincinnati? Pretty close to the geographic region. Good Football team right now. Historically they had been pretty good in basketball.
Notre Dame is the team that should join the Big 10 as far a perfect fit goes, but they won't because of all the reasons stated.
I heard a former big ten football coach on the score saying NDU no longer had an appreciable financial tv revenue advantage when compared to the financial benefits joining the big ten would bring. I think it was Jerry dinardo or something like that.