I disagree with Matt entirely. I don't want any part of a cold weather BCS game, and it's all about the BCS format.
I'll concede that, if a team is really one of the best, it should be able to win in all conditions. That's a given. The issue I have is that a cold weather BCS game wouldn't always just be a cold weather BCS game. It would sometimes be the national championship game.
Things are different with the NFL playoffs. Sometimes you play indoors, sometimes outdoors in mild conditions, and sometimes outdoors in the snow. The variety there presents different kinds of trials for teams to face as they try to prove themselves. That's great, and I'm all for that. A fluky occurrence regarding the weather might happen and an underdog might win as a result, but the tournament format weeds them out fairly well (only 12% of Super Bowl winners and 11% of overall participants have been wild cards since the wild card was introduced in 1970).
In college, we only get one shot with the determining-a-champion thing. Two teams, one game, and that's it. I want as little chance of a fluky outcome as possible.
It's impossible to factor out everything, of course. Sometimes Colt McCoy will get hurt in the first quarter, or there will be a controversial pass interference flag right near the end. Those things you can't help no matter what. However you can control where you put the game, and holding it in a place that's unlikely to have freezing temperatures or precipitation is a smart move. I'm not even thrilled about artificial turf in championship games as it's unnatural and a greater threat than grass to shred someone's knee ligaments, but FieldTurf is good enough at this point.
I'd be more open to a cold weather game if it was part of a playoff. But as a part of the BCS? No way.