Guys guys- look closer! There are some interesting new things here I think
Proper shadows! In the first part. notice how the shadow bends and moves across the waves? In FSX the aircraft shadow is still a simply projected plane- It won't change shape over a surface. Notice also how the colour/depth of the shadow now changes depending on viewer angle over water?
The next part gets me excited- At about 0:26 what happens to the shadow on the wing? It disappears! What causes it to disappear? The terrain! In FSX, if you are flying in the shadow of a mountain, this won't cause a shadow on your aeroplane or another object. In these shots the terrain is casting a shadow on the aircraft by the looks of it....which leads to the possibility that MS is adding global lighting (similar to XP10) so objects (such as buildings) cast shadows on other objects (such as aircraft) and lights cast themselves globally as well (i.e. shine a landing light onto the side of a hill and have it properly illuminated!)