I think there's no such thing as free will in any case. At least for the religions notion of free will floating around in my mind:

  if (!is_fully_deterministic(universe) &&
      have(universe, RANDOM_CHOICE))
      assert(!have(universe, FREE_WILL));
  if (is_fully_deterministic(universe))
      assert(!have(universe, FREE_WILL));

The only remaining way to have that sort of free will is to have non-random laws that somehow are not fully deterministic. I'm not sure what that would mean. Non-random -> deterministic, no?

However, even in a fully-deterministic universe, or a mostly-deterministic universe, we will appear to have free will in so far as we cannot read minds and we cannot predict next states for the universe on any scale, with any accuracy, and in any amount of time that would be practical for determining e.g. whether someone is at fault for their actions. And it's pretty clear that this will always be so.

The question of whether we have free will, then, is sort of moot. From a social perspective we have little to choice but to act as if we do have free will.