The assumption that we are mainly operating under right now is this: A WORTHY conference champ will be left out.

I went back through the relevant "playoff worthy" teams from the BCS era...and these are the years where MORE than 4 conferences or significant Group of 5 schools were in play:
1998
2002
2005
2007
2008
2011
2013

So, about half of the years would have had a POTENTIALLY worthy team from more than 4 conferences.

That said, don't forget that we've seen major consolidation. The Group of 5's schedules will probably be worse (hurting SOS).

The ACC champ was only really relevant in 4 of the 9 years that they had a CCG. The Big Ten champ was only relevant in 1 of the 3 years it's had a CCG. Even the Big 12 only saw a relevant CCG in 2 of the last 4 years it had a CCG.

All of that to say...it could be a moot point if one or two conference champs (let's say a 10-3 Ohio State or a 10-2 Oklahoma) aren't even in contention for the CFP in 2014.