We are doing some post-processing effects like full-screen motion blur, some HDR glow effects, heat shimmer, and some others. The implementation of these at this point is hardly relevant, but we are not using an accumulation buffer for the motion blur.
As for normal maps vs. parallax mapping, as I'm sure you are aware, their usefulness varies depending on the situation. Therefore, sometimes we will be using parallax maps, sometimes normal maps, and sometimes another method entirely.
These types of choices are without a doubt the questions to be asked at the polish stage, which we have obviously not gotten to yet. I appreciate the interest in the implementation details, but I never like to lock down what methods we use. Rather, we provide as many options as are feasible so that we can tweak out the effect based on performance and visual integrity.
Hope that makes sense.
--Joel