I think one way of clearing the picture up some is to look at the conferences and where they stand. I'd break them down into four categories.
1: The completely safe from all external threats grouping
Big 10
SEC
Pac-12 (While their finances are not as good as the first two, they're still rock solid in terms of stability).
2: The Hunted
ACC (Yes they are in a better position than the Big 12, but they are still using coercion to keep their teams around. If their grip weakens, North Carolina, Virginia Tech, FSU, Clemson, several programs could look at their options).
Big 12
3: The at least some fans show up to watch them conferences
AAC
Mountain West
4: The garbage bin of the FBS
C-USA
Sun Belt
MAC
Now, we can't forget about Notre Dame. They're one of two teams that could pretty much pick any conference they wanted to join, if they'd just become an equal member. I suspect one reason the Big 10 hasn't gone to 16 is simply because they don't have Notre Dame. Texas is of similar if not greater value, except perhaps to the SEC who already has Texas A&M. Anyway, out of all the possibilities in the near future, the Big 12 falling apart remains the most likely scenario.
The deal that seems most likely is one that was already considered basically. Three things stopped it last time. A: Texas A&M got cold feet, B: Texas didn't want to share, and C: The powers that be decided they didn't want to see the Big 12 fall apart. RobK makes an interesting point though, at the time it seemed like they were printing free money when it came to the growth of revenue, now that things have slowed they might decide its in their interests to let one of the conferences fall apart so that money can be used elsewhere.
The big obstacle now though, and one that could still present itself would be the LNH. If Fox is going to be giving up a piece of the action in the Big 12 (while they would be somewhat compensated via more Pac 12 content) they might not be too happy if they watch ESPN get a piece of the Pac 12 Network (which almost certainly would have to happen). One thing that's interesting is that ESPN and Fox both didn't want the Big 12 to expand, so they are one of the reasons the conference is still on thin ice. Anyway, let's assume it happens and Texas, Texas Tech, Oklahoma and Oklahoma State all go to the Pac 12. The Pac 12 then partners with ESPN on their network, they add add states with a population of over 30 million, they have some games that air earlier, etc... it would seem that if nothing else the Pac 12's revenue stream would improve.
What then though? What about Kansas, West Virginia, TCU, Iowa St., Baylor and Kansas St.? Well, this could turn out to be a case of low hanging fruit for the ACC. I could imagine the ACC adding Kansas, and having some interest in Baylor. There's one wrinkle though, they have Notre Dame as a partial member. If they just added Kansas it would make things lopsided, but they'd be adding a strong basketball school, an athletic department that's in great shape (CNN ranks them 28th among public schools in AD revenue, so hard to imagine it hurting finances), not disrupting their football powers, and perhaps most importantly, they'd finish off the Big 12 (who once flirted with Clemson and FSU) and solidify their status as one of the 4 super conferences. For the sake of argument I'm going to assume they try convincing Notre Dame to become a full member instead of adding Baylor. It should be noted though, that while the ACC's status as a power conference would be safe, they still would remain a potential target for SEC or Big 10 expansion in the future.
The AAC and the Mountain West both have 12 teams. The AAC has 31K average attendance, the Mountain West has 24K. Sagarin has the AAC rated higher as a conference as well. Considering the fact that TCU already tried to join the Big East once (before it fell apart), I think it would make a lot of sense for West Virginia, Baylor, and TCU to head over to the AAC. The AAC already wants inclusion to the power conferences, and this would put them closer to the ACC. The fourth one would be a little tricky. Iowa St. and Kansas St. both are in fairly small states and have athletic departments in similar shape. Boise St. was going to join the Big East as well, but they're a one trick pony. Then there's BYU, who is should be noted has better attendance than every school mentioned so far (other than Notre Dame and Texas). Either way though in that scenario the AAC should come out in a strong position and the Moutain West would likely add what ever is left over (BYU would almost certain join a conference with the Big 12 off the table).
I don't really see a likely scenario that involves either the Big 10 or the SEC. It also seems like a real longshot for the ACC to add Oklahoma. The biggest question if this Pac-12 merger were to happen would be if the Big 12 could somehow survive with just 6 remaining teams, or if something topples them. This wouldn't really be a debate if they'd gone to 12 teams, as for instance BYU and a Florida school would have been more than enough to keep them afloat.