Updated with correct Shield Block uptime, as well as Glyphs (one glyph across two classes effecting mitigation =
http://wotlk.wowhead.com/?item=43425) and filling in the ranged slot (Initially left out as sigils and idols don't have equivelants)
It seems we are indeed 2-3% behind warriors in blunt mitigation all the way along, and anything from 4-7% behind in damage taken over time.
Concerning, I'll update the OP rather than mislead.