I believe the Royal Vampire Armor in Dawnguard had some physics modelling. Or so i've heard, never noticed myself
But there are some awesome armors using the HDT SKSE plugin that do have separate moving parts and flowing skirts. So it is possible to achieve even with the Skyrim version of the engine.
Yeah, tried Fallout 3 the other day, and the character actually
slides forward. Even continuing to slide for a moment after releasing the movement keys
The jumping is really bad too, very difficult to climb on top of anything. And of course the rule of thumb, if a deathclaw can't fit trough it, a bullet won't fit trough it either :rolleyes:
But those things were improved for Skyrim (except that last), so maybe they'll further improve for F4