Don't want 12-20 teams.....like some have posted would water it down.
I like the idea presented of 8 conferences and you win you are in. The only thing I would change a little here is make it the 5 big conferences (SEC, ACC, B1GTen, Pac-14, and Big 12) then , to keep the politics out of it, just pick the 3 highest ranked teams that are left and make them the 6, 7 and 8 seeds.
That way, the regular season still means something, but the teams that may have had 1 slip up or simply went 11-1 but maybe their first lost was in a conference title game would still have a chance.
It would still matter to try to want to win your conference title because if you lose, you are not guaranteed to get in the 8 team playoff, and it would depend on how far you drop. So even though you could lose the conference title game, it would still benefit you to win it or to at least play hard and not get blown out.
To me, 8 is the perfect number that allows a true champion, allows one "bad ref call, injury or bad luck on the field" to not necessarily cost you the season (see Duke).
20 is just too many.
