As I mentioned in my Rogue and Feral post the other day I have been bouncing between characters that I have been playing. One of the changes that I made while leveling my Warlock was to try out Destruction. I went with one of the popular Demo/Destro builds. I had tried Destruction prior to WotLK and just could not get into it. At the time I was still running around with my Mage as Fire and it just felt like a Fire Mage with a pet. My favorite talent build for Warlocks is still Affliction and I went back to it yesterday.
Anyway, comparing Shamans and Warlocks does not usually occur because the melee and healing aspects of Shaman sort of blur the comparison a bit. However comparing the Elemental build/rotation to a Warlock focuses the issue a bit and surprisingly there is a bit of similarity between the Elemental Shaman and Destruction Warlock build and play. Now it could also be argued that Fire Mages and to a lesser extent Arcane could also be included in this comparison but the key point of overlap does not hold out.
By now you must be wondering what the hell I am talking about. The similarity I found was in the opening and basic rotation.
Open with Fire Damage/DOT -> Direct Damage cool down spell -> Spam quick cast spell until cool-down while maintaining the DOT. Now both classes have varying talents to increase and modify critical strike chance but when I was spamming the basic rotation on the warlock while questing this similarity occurred to me.
Now the variation that is similar with the Arcane Mage is the reverse. Spam Arcane Blast until Arcane Barrage procs or 3 stacks of AB buff/debuff. Cast Missile Barrage and start the Arcane Blast spam. Now this is a very mana intensive rotation but the damage is good. I will not say it is the best, I believe the current theory-crafting max damage rotation for mages is a fire/frostfire build.
With patch 3.2 coming soon, improvements or other observations could be rendered moot so I will revisit these 2 classes after the patch as well as have some other stuff to talk about I am sure. The core rotation similarity between the two I thought interesting enough to point out.