There is no doubt that most administrations go through a process of musical chairs when storm clouds appear on the horizon. Holder is important in that conservatives and those who hold the U.S. Constitution to be the standard upon which American jurisprudence is established have been gnashing their teeth and trying to remove him from federal offices since the Clinton W.H., more than twenty years ago.
IMO Holder is one of the pillars upon which the agenda of TPTB depends. The real executives in this administration are Jarrett, Holder, Napolitano & Sebelius. Due to the appointed nature of their fiefs and the cowardice of those in the Senate who confirm such nominees, these four remain the four most dangerous persons in American politics. In terms of throwing someone under the bus as an example, Holder would be a very good start. With enough pressure, Bama would eventually cut off any of the above [with the possible exception of Jarrett] just to get the media disgruntled Dems and Tea Party sympathizers off his back.
Bama is a figurehead, a symbol. He is not an ideological being. As long as T real PTB are satisfied with the progressive movement of their agenda, Bama is free to boogie with Beyoncé, get down with Reggie Love, shoot hoops with 15% accuracy before the cameras and to cheat on his golf score if he so wishes. He is set for life financially and in terms of his status in history. As long as he doesn't cross the line and break with his masters on any of the key issues, he'll be free to continue his carefree life as the hippest cat ever to inhabit the White House. That is all he really cares about.
The crash is indeed coming despite the switcheroos yet to come. Everyone seems to know it and no one seems to care.