Quote Originally Posted by dragonseth07 View Post
True, but then there is a best spec per fight, and you're expected to switch to that before the fight.

WoW's system in Warlords was exactly this. There were talents for different situations, and it was expected that you change spec on a per-fight basis. At that point, your character no longer had a build. Your build was every talent based on what you fought.
on the other hand, would be interesting for the community to try figuring out to balance their spec for specific fight, and the speed runner to try out different spec for faster kill.