Never on 15 December 2014
From those pics it looks like they keep the original, possibly pre rendered, shadows and add the real time shadows.
However, it looks like the light source for the new shadows come from a different angle. So, for example, the pipe toad's travelling in has a shadow cast to the bottom right. The shadow of toad himself is not only much bigger than the shadow of the pipe but also cast towards the bottom left.
