Hate to dredge up an old topic for the sake of curiosity, but did anything ever come out of this? I've searched the guide, the forums, Trello, and even the old Kickstarter, and can't find any signs of its implementation, not even a place in the backlog.
Blend shapes would be a major time saver for cases where arms and legs are bent at extreme angles (automatic FFD deformation, set to blend in between specific rotation values), or for when a character requires facial animation that goes beyond simple texture swapping. (eg: sliders for eyes ranging from 'wide open' to 'shut tight', or subtle FFD deformation to simulate face rotation)