Taking conference champions only basically implies that we should screw the SEC team(s) that fell short of winning every game in a far superior conference, while rewarding mediocre teams that win inferior conferences. #1, #2, #3, #4 makes for a MUCH better overall playoff than #1, #3, #5, and #10. How do you justify giving #10 a chance over #2, #4, #6, #7, #8, and #9? Bad thing is, this year was as drama-free as it could go in the conference championship games, outside of the mild upset in the ACC. What happens if UGA beats LSU, yet is ranked lower than 4 other conference champions? You end up with(apparent heir to) #1 Alabama LEFT OUT of said playoff, while the SEC possibly gets no representative at all, even though they've got 5 teams in the top 12. So, it is easy to see how this could lead to split national championships to a greater extent than even the current setup.
If you go back to the end of the regular season, your talking about these teams playing in conference championship games for a chance to play in the national title playoff:
#13 Michigan St vs #15 Wisconsin
#5 Va Tech vs #20 Clemson
#1 LSU vs #14 Georgia
#9 Oregon vs unranked UCLA
#3 OK St vs #10 Oklahoma
and taking the 4 highest-ranked winners.
In this scenario, by letting in #10 Wisconsin, Bama gets screwed, Stanford gets screwed, Arkansas gets screwed, Boise gets screwed, KState gets screwed, and South Carolina gets screwed. You reward a mediocre regular season in a bad conference over a mediocre regular season in a superior conference IMO...
Only "fair" way to do this is #1-#4...