At the risk of ending up on message board geniuses, I'll throw this thought out there.
With the financial disparity in the Televison contracts between the ACC and the B1G/SEC; the only way I could see an ACC full on merger with one of those two conferences working would be via a promotion/relegation model like the Pac-2 and Mountain West/AAC are talking about.
Under this type of merger, the B1G/SEC would be considered the Premier League equivalent and the ACC would be considered a tier down. This way both conferences could maintain their current TV contracts; with only teams that get relegated being out any money.
To preserve rivalries in this type of model a certain number of cross conference games could be allocated annually with designated rivalries always being allocated as one of a team's cross conference games should one team be in the ACC and the other in the B1G/SEC. I would propose 8 in conference games, 3 games against the higher/lower tier conference, 1 game to schedule out of league.
Why top teams in the B1G/SEC might consider voting in favor of this: Confident enough in the strength of their program to not have to worry about relegation anytime in the near future (Truer for top B1G teams than teams in the top-heavy SEC) with an opportunity to absorb teams like Clemson/FSU/NC/Miami without diluting distributions while simultaneously shedding dead weight at the bottom of the conference.
Why bottom teams in B1G/SEC might consider voting in favor of this: Trying to solidify a mega conference they are a part of as a hedge against the top teams breaking away and leaving them behind.
Why top ACC teams might vote in favor of this: A path to the B1G/SEC without having to find a way out of the grant of rights or paying a huge exit fees.
Why bottom teams in the ACC might vote in favor of this: Hedge against being left in a severely diminished conference if top ACC teams leave for the B1G/SEC. Still a path to the college football playoffs in the lower tier league due to cross league games should the lower league champion rank high enough.
Why top teams in the B1G/SEC might vote against this: Even the thought of being regulated is untenable.
Why bottom teams in the B1G/SEC might vote against this: Reduced athletic department financial resources and lower prestige if relegated.
Why top ACC teams might vote against this: Don't want to have to wait until they win the ACC to get promoted. Does not stick it to Wake Forest enough.
Why bottom ACC teams might vote against this: Not wanting to risk being stuck in a football league where Clemson, FSU, NC, and Miami are perpetually replaced with Rutgers, Illinois, Indiana and Perdue. Does not stick it to Wake Forest enough.
Why Wake Forest might vote against this: Inconceivable. They would be all in.
The legal side of this type of merger would probably be easier to work out with the SEC since both conferences are primarily contracted with ESPN for Television broadcast rights; but the SEC is probably less likely to entertain the idea since they seem somewhat inclined to maintain some sort of geographical footprint.
Since the B1G and ACC both have west coast teams now; this type of merger would potentially help reduce travel cost as the former PAC teams could designate themselves as rivals to minimize cross country travel.
That's probably enough time in fantasy land for one post.