I just read a impression about journalist (Dutch) that had seen a presentation about Skyrim and it had some combat in it. He said that the animation were basically the same as in Oblivion.
It's clear Bethesda's spent time working on the animations with its new Creation engine, as the sword swings and mace slams of combat have a more natural look. Bandits stagger and sway and your screen and equipped gear shake as slashes are exchanged.
While I would normally make a mocking comment about IGN here, based on the trailer we saw, I would have to say they have probably improved... That and the brand new animation system and all. :shrug: