Well put. That's as good a cliff notes version as what we are seeing happening.
I would add to that, after going through pages and pages of expansion thread in The Shag, is that the Big XII goes as Texas goes; they are the key to that conference. The best thing for UT is to be the the biggest fish in the "Texas Conference". If Texas were to leave the Big XII, it dies... and it would die quickly.
To a lesser extent, UNC is the Texas of the ACC. If UNC leaves the ACC (or as the Shagsters call it, "ESPN's pet"), it will be a slower death, but it would be the beginning of the end for that conference.
Despite what people might think, I don't think there's any chance in hell ND will ever come to the B1G. There's a better chance of Texas joining the conference than ND joining, if that gives you any idea. The domers will join the Big XII or the Pac X before considering becoming a full member in the B1G. That'll never stop Jimmy D from pursuing them like a stalker, though.