I liked the expansion of your PC appearance, gender/racial specific animations, partially destructible environment and bar brawls.
I was disappointed with the lack of major branches in the main quests and the need to recharge magic items (why are armour enchantments permanent and weapons not?). By far the worse news for me was the lack of a 64bit exe, which is galling for some of the same reasons Kermit mentioned.
Everything else was of minor consequence to me, or at least design decisions I agreed with. However, unless they are keeping some major revelations under their hat, I'm beginning to feel that Skyrim will not be quite the evolution in terms of game play, roleplaying depth and cultural uniqueness I'd hoped for. I'm sure it will still be an improvement, just not quite as far-reaching as I'd dreamt.