I'm glad that Armitage is leaving. He's no saint, by any stretch, and in his past has worked against America's interests when they differed with his own personal ones. He also sided with Kerry about leaving MIAs in 'Nam, regardless of actual sightings.
Armitage is one of the main ones at Foggy Bottom that has made it the dysfunctional agency it is. Good riddance to bad rubbish.
I recall reading that he was Rumsfelds first choice for his deputy.