Yes...if the new 4 team playoff goes by the RPI method, the SEC or Big 12 would have a better chance of getting two teams into the playoffs than the ACC would have with one team.
I always see the Big 12 and SEC getting at least 1 team in every year. I see the Big 10 probably getting one in every year as well. I see the PAC 12 trading a spot on and off with the likes of a 2nd SEC team or maybe Big 12. Plus, you have the Boise State's of the world that could go undefeated and finally have an RPI strong enough to get in (if they play the Oregons and VTs etc. pre-conference).
This move seems like a no-brainer for Florida St. and Clemson.
I put something together that shows the 6 existing AQ conferences that shows the average BCS ranking of the conference champion. In the event that the champion that year is no longer a member, I substituted it with the highest ranked member outside of that group. For some previous champs, like Miami in the Big East, I did not give them credit for their old or new conference since they had a champion.
I did have to substitute Boise in for the Big East a few times, but overall, the numbers worked out for the top five conference fairly easily. The Big 12 took a hit in the early 00's because we couldn't claim Colorado in 2001 (#3) and had to take Texas (#7) instead.
There's other crap I had to throw in there, too. For example, in 03, we were the champs, but under the most recent proposed format, if there aren't four conference champions in the Top 6, they'll take the highest ranked duplicate or independent. For us that would have been Oklahoma (#1). I took that into consideration.
The Big East didn't have anyone on the list outside of Miami in 01 and 02, so I gave them a default value of 25 for each of those years since that's how far they extend out the rankings now.
Here are the average conference champ rankings in the last ten years:
1. SEC (3.4)
2. Big 12 (3.8)
3. Pac-12 (4.0)
4. Big Ten (5.7)
5. ACC (12.2)
6. Big East (13.7)
As you can see, there is a very clear divide. The math may be a tiny bit hazy, but the demarcation is still very clear.