I've posted a similar post in the warlock forums, it seems to be well received. I'm hesitant to recommend it as strongly for all dps specs as I don't know how well developed it is for them right now, so keep that in mind. It's extremely basic but there seems to be some interest in a detailed one and I'm working on figuring out how much detail I want to go into.

http://www.youtube.com/watch?v=7UE_W2spSLQ

The links for SimulationCraft and Reforge Lite can be found in the video description.