Having him serve as SECEF for 911 and thereafter was a blessing for this nation. I hope history is objective in its interpretation of events.
For him, this was his last hura. There were no political ambitions post SECDEF and that was known. He did what he knew was right regardless of political interests and peoples feelings. Highly competent, he was demanding of people and this too was known albeit resented by some that found themselves getting grilled. His goal was to reform the government bureaucracy and push the transformation of the DoD (talked about for years but never done) ahead. Along this path he ended up stepping on the turf of some when he personally got involved in killing the Crusader and Comanche programs, decisions that in hindsight make complete sense. He pushed for the Brigade Unit of Action and large-scale restructuring of the Army which had become top heavy. To this end he brought in a retired general to become the Chief of Staff (Shoomaker) bumping those in the cue waiting. He made many decisions that were frowned upon by various politicians or senior military leaders (Some like Shinseki with political ambitions and also falling into the administrations back), but it cannot be said that he lacked vision, that those visions were in-congruent with the needs of where the DoD needs to head, or that he lacked resolve and organizational competence to push things through. He was a mover and shaker and if you were hoping for an easy ride, life would be hell under him.
(About Shinseki) Heralded by the liberals he simply offered unrealistic solutions of 300,000 troops in Iraq (where were they to come from?) in Congressional testimony intended to make the administration look bad. These troop levels are only maintainable for a short time of about one year, after which trying to maintain these levels is impossible if troops aren't to stay deployed on a continual basis for over 18 months with a one year reconstitution time. His letter of resignation is a class act, juvenile one expects better from a Lieutenant that gets canned and asks for a release from active duty (If you can find his resignation letter it's worth reading). Of course after Obama gets elected in 2008 he finds himself immediately heading the Department of Veterans Affairs. This of course isn't news worthy material. So goes the politics of those in the most senior ranks and it must be noted that Shinseki’s actions in hindsight unlike those of Rumsfeld were obviously self serving, shortsighted and did not consider what the best course of action for this nation.