For those using Dr Damage, dont hold your breath for an update for 3.1 or beyond. The main developer has left the game and no one has yet picked up the development process for the addon. There is however a sucessor in the works called "Mr Damage" which can be found here:
http://wow.curse.com/downloads/wow-addons/details/mr-damage.aspx
I believe at the time I write this it only shows values for DK's but the author promises to have more classes added soon.
It looks like the people working on these addons to succeed Dr Damage are going to keep each class separate. They released the Warlock version today:
http://wowinterface.com/downloads/info13191-MrDamage-Warlocks.html#info