In short: helmets matter. They aren't the end-all-be-all, but they do tip the scales.
On the other hand, Wisconsin should have just won the darned conference championship game. Sigh.
Back to the point at hand: an 11-1 Ohio State has a decent shot at beating a 11-2 Wisconsin conference champ into the playoff. It's not a done deal, but it's not hard to imagine. Easiest way to imagine it: Ohio State loses a close game to Penn State. Wisconsin loses to Michigan, but beats Penn State during the season. Penn State wins the head-to-head against Ohio State so it represents the east in the CCG. Wisconsin beats Penn State again in the conference championship game. 11-2 conference champ Wisconsin, 11-2 conference runner up Penn State, 11-1 Ohio State (which, after losing by a hair in Happy Valley, crushes everyone else in its wake, including leaving a nasty blue and maize stain on the turf at the Shoe).
Think about how the polls would treat these teams. Wisconsin will be about 12-13 if it beats Nebraska, then will drop to around 17-20 if it loses to Michigan. If Penn State beats Ohio State this weekend, PSU moves up to the 5-6 range (Stanford or ND will drop, as will OSU, but OSU will stay high if it loses a squeaker: probably 8 or so--probably above the loser of Stanford/ND).
Michigan, fresh off the win against Wisconsin will move up into the 10 range, giving Penn State a further boost when they beat the Maize--who, losing to a top 5 team will drop into the 15 range. Wisconsin, not having beaten anyone of note, will move up with wins into the 15-17 range, then topples top 5 Penn State in Happy Valley. Wow. Big boost--maybe up to 10 or so, depending on what others do.
Ohio State, meanwhile, keeps crushing teams, and keeps sneaking up--surpassing Penn State when it loses at home to Wisconsin. Ohio State is now around #5, and finishes the season with a coronation against Big Blue, stomping then 15 Michigan at home. The winner of Stanford/Notre Dame stumbles down the stretch, Alabama (already knocked LSU down) and Georgia knock one of each other out of contention for the playoff (no one wants them both two years in a row), and there Ohio State, at 11-1, #4 in the country sits while #9 Wisconsin plays #10 Penn State for the conference championship. Frankly, even if Penn State wins that game, it might be a tough sell to vault over Ohio State. But if Wisconsin wins, no chance it gets the nod over the 11-1 Buckeyes.
I've put way too much thought into this, but there you have it.