The biggest win for the new approach is that cookie cutter builds will be usable when you look at the INDIVIDUAL, but when you start talking group compositions, the water gets a lot murkier. You may find that this talent synergizes best when you're using it at the same time as someone else uses a certain talent. Or talent X may be dependent on whether you have class Y in the raid. If there's more than one of your class, perhaps you each want to take a different talent from the tree, or stack all on the same, or somewhere in between.

The advantage of such flexibility is that it's not just a numbers game - it's about synergy and planning and strategy.

Or, at least, that's the goal.

Yeah, synergy. So now instead of everyone needing to determine their optimal build based on their gear, they have to figure out their optimal build based on *everyone else's* gear and builds. Of course, Blizz won't (I hope) be designing fights around this idea that everything will be optimized to this degree, but the hardcore raid guilds will still pursue it, and the lazy players will still pick things at random, then be criticized for it.

I'm guessing the idea of "no wrong choice" is more that the delta between the "worst" and "best" builds in terms of measurable personal performance will be minimal to non-existent. Pre-Cata, that could be a very dramatic difference, and even now there is still a gap.