James Fallows has the definitive commentary here.
Shinseki had the courage to tell truth to power in the run up to the Iraq War. After he retired and was shunned by the geniuses behind the glorious Iraq fiasco he never publicly spoke out. He didn't seek to make money by becoming a "talking head". There's a certain dignity to that.
President Elect Obama picking him to head the VA can only be called "poetic". Decorated and severely injured combat veteran who in essence opposed the Iraq War heads VA.
The New York Times has a good article on the pick and the man.