#4 - Oct. 28, 2010, 5:30 p.m.
Due to recalibrating expertise for Cataclysm, level 80-83 creatures (which includes bosses) dodge and parry less, so you need less expertise, 23, to be exact. Sorry we didn't announce this. I would classify it as an unintended consequence (though not unknown) and not a desired change on our part.
At level 85, you will need 26 again.