Shinseki is a career soldier who lost half a foot to a Vietnamese landmine. Prior to the Iraq invasion, he was best known as a champion of transformation in Army planning centered around intensively-trained "Stryker" brigades. This, along with personality issues, put him at odds with Donald Rumsfeld, whose own vision of Army transformation was about lower troop levels and greater reliance on high technology.
After the invasion, Shinseki has been best known (outside the military) for his testimony before Congress that the troop levels required to pacify Iraq would be far higher than those planned on by Rumsfeld's team. For this he was derided by such military geniuses as Paul Wolfowitz (who found it "hard to imagine" and "outlandish" that more soldiers would be required to hold Iraq than to take it).
Obviously, he was right and they were wrong, which is easy to imagine, since Rumsfeld and Wolfowitz are incompetent fools who in a rightly-ordered world would never have advanced beyond branch manager at a modest Midwest retail bank. If, indeed, Rumsfeld got that far with his limited social skills and inability to take responsibility. But we digress.
Anyhoo, Shinseki knows the Army at its uppermost levels, and he has demonstrated his concern for soldiers. Given the scandalous mismanagement of the VA under Bush, we fully expect him to run a tighter and more humane ship, even if America's changing circumstances require him to do it on the cheap.