As long as the Big 12 doesn't beat up on itself, it will get a team in. If any of BU, OU, OSU, or TCU wins out, that team will be in the playoff. The problem for the Big 12 will be if those teams spread out the wins.
If Clemson loses, the ACC is out. I think Notre Dame is very overrated right now and even if they win out I think they could be left out. If you replace the names on the jersey for both Alabama and Notre Dame with Vanderbilt and BYU, they wouldn't even be in the top 10.
Notre Dame @ Stanford might end up being a play-in for the playoff (although Stanford would have another game to play after that still).