I brought my Night Elf Death Knight, Cordelaine, into her first instance on Tuesday. The instance Was Hellfire Ramparts, and she ran with another 65 Death Knight (a human and the tank), a 65 holy paladin, and an 80 mage. Cordelaine is currently blood specced and at level 58 so she did DPS, or at least tried to. I was only hitting about half the time and I couldn't really remember what I was doing since I hadn't played her in weeks.
We cleared the instance easily despite my melee incompetence, but no one needed any of the drops. It was all hunter mail.