So are some of my thoughts (and this has been my #1 idea for awhile now, though there is probably about a 0.1% chance it happens):
1. If the Big Ten adds Notre Dame and stops, it fails to accomplish its goal of spreading the conference footprint to the sunnier parts of the USA.
2. It is clear from what I read that academics are just as important than athletics to the B10, if not more so.
3. By Notre Dame, the B10 would be demonstrating that it is okay with adding another smallish, private school.
4. Geographic continuity is important, even if it isn't stated.
5. The B10 may be considering a 4x4 quad system.
6. The SEC may poach Virginia Tech or others, so the ACC as it now looks may be in trouble.
7. Adding Notre Dame and 4 ACC schools could be a real possibility. The 4 ACC schools could be an entire quad, so current B10 schools wouldn't have to be broken up as much.
8. My choice for the 4 ACC schools would be Maryland, Virginia (two large states, plus the DC market, quality academics and sports), North Carolina, and Duke. In this scenario, the only thing lacking is consistent top-15 caliber football, but those schools are very good at a lot of other sports, so that may make up for their lack of power in football. It adds what is academically the best large private school in the South to the best large private school in the Midwest and best Catholic school (academically) in America. It spreads the conference out without spreading the conference thin, and it improves the conference dramatically in M&W basketball and baseball, the three most prominent NCAA sports after football. I know this is a major long-shot (almost laughably so), but I think it would be an ideal situation.