Using Greg Craig's departure as his hook, Lloyd Grove has an amusing roundup of erstwhile friends and allies--including Van Jones, Tom Daschle, and Jim Johnson--whom Obama has tossed under the bus in the past couple of years.
I don't think all of them warrant inclusion: the top commander in Afghanistan, David McKiernan, doesn't really fit the mold. (That was more a Gates/Mullen/Petraeus thing, and Obama never appointed the guy to begin with.) Still, it's a fun reminder that Obama doesn't fetishize loyalty the way his predecessor did.