RDave,
I want a playoff more than anything in college football, well except for an invite to a Big 5 conference, but the old argument of having players play 5 more games will always come up. It seems that a game from the schedule would need to be dropped and we all know what people on this forum think about losing a Saturday game! Don't see that happening. Home games in the first round may help quell this argument.
The other major flaw with a playoff with 24 teams is fan travel. Travel to a single bowl game, in mostly fun cities, is already an issue as evidenced by some of the low turnout in the bowls played thus far. Possibly five plane tickets, hotels, tickets, food, gas etc would likely price some fans out of the entire playoff experience.
As it stands there are 10 conferences, not including independents. Have all 10 conference champs in plus 2 at large, same format as you describe from there on out. Pay each conference a hefty sum of the profits so they get rid of their conference championship game and you're not really adding that many more games.
I love/hate this conversation!!!