I can help.
First, the cabinent is a rediculous high stress job as one could emagine. 4 years is enough for many. Big change in guard is normal.
Second, some had already planned to leave to move onto other things.
Third many are hold overs from the 8 years of horror administration, kept for transition and partisan purposes, those "Clintonites" are being asked to leave so Bush can really get to work.
Fourth, everyone knows the differences of opinon between Rumsfield and Powell, and the ongoing struggle to modernize the military.
Fifth, despite extrodernary changes in the first administration, you aint seen nothing yet! And he needs the right people for major tax reform, medical, ect. And, hopefully public land policy.(reform endangered species act, stop wilderness, back country designation, 100% rs2477 uphold)

I dont think youll find any folks resigning under disgust and writing books on the crisis, like with Clinton. <img src="/forums/images/graemlins/barf.gif" alt="" />