Here's how I see the final 4 playing out as of now, barring upsets (which obviously you can't rule out anymore)
Bama - In
OSU/Michigan - Winner in, loser out (assuming they also win Big 10 title game)
Clemson - In, assuming they hold on to win ACC, which they are on track to do.
The last spot then comes down to Louisville or Washington IMO assuming both win out. Do they reward Louisville who probably had a better resume, or do they reward Washington for a conference title?
If we have some crazy upsets, things like Wisconsin, Oklahoma, or a 2 loss Michigan or Ohio State start to come into play. Will definitely be an interesting final few weeks.