So this year if they had 12 and assuming no major upsets
the 4 byes would be Georgia, Michigan, TCU, USC
The next 2 best champs are the winners of Clemson/North Carolina and Tulane/Central Florida (they'd be the 12th seed)
An upset by Purdue would move Clemson into the bye line if they beat UNC (and Purdue would probably be the 12th seed with the AAC champ as the 11th), but I suspect KSU, Utah, or LSU would all jump Clemson (even assuming they beat UNC). A Clemson loss and they are probably out, though UNC would still be in, though may be behind the AAC champ as they are currently 23rd behind both Tulane 18 and UCF 22.
The title games though if the favorites all win, could absolutely affect the bottom of the bracket as I think only the top 4 and the next 4 i.e. Ohio State, Alabama, Tennessee, and Penn State would be locks to stay in the top 12 regardless of results. Those final 2 spots could be very interesting between Kansas State, Utah, Washington, and Florida State. By virtue of a conference title game loss, do KSU and Utah drop out of the playoff that they'd currently be in?
Sucks we have to wait 2 more years for this. It'd be pretty darn cool to have it now.