There are more bones in the skeleton not less. It is exactly the same(bone lengths are different though) but with the addition of 2 pauldron bones.
support for custom environment cube maps. and the ability to add a mask texture that controlls the level or to completely mask off areas being affected by the env map.
Flip controllers are out. I actually tried as well. it just hangs the geck.
the terrain LOD algorithm is improved.
normal mapping is zillion times better on vannila assets.
the whole invisible hair/ears while equiping a helmet is somewhat solved. ears are no longer a separte nif, and are part of the head mesh. there is a separate hair piece that gets swapped in when equiping headgear. there is facial hair
nifs use a string listing.
yep, the texture baking is more complete than was in oblivion. and also slightly more exaggerated.
alpha sorting works better imo.
form lists and texture sets.