Locke's decision making is the most obvious reason for that loss. There is no way Longo is coaching him to throw the ball that resulted in the pick-6. Wisconsin needs to grow its players--we won't get players who come in as stars right away, particularly at the QB position. And I agree with BAB that Penn State looked better on both sides of the ball (except maybe special teams?) throughout most of the game.
The USC loss is the one that really grinds on me. And, yes, I agree that the inability to sustain drives put the Badger D in a bad spot against the Trojans (and others). The wear on the defense is significant by the second half--too much time on the field. Fellow Badger fans may not like it, but I think we actually need more "dink and dunk" plays--pick up 5-7 yards at a time, with fewer deep balls. The more of those short routes that work, the more the deeper balls will open up. I'm not opposed to this style of offense, but we haven't had a QB that has run it right yet. And maybe it's just to early for Locke. QBs--especially Badger-level QBs--need time to develop.
But if the team doesn't win two more, I wouldn't be surprised if Fickell makes the change. If they beat Iowa this weekend, it will calm the nerves. If they aren't competitive against Iowa, that will be a real problem.