I already saw some of those features on a different commented gameplay trailer. They forgot to add that you can disarm enemies and use their weapons against them. There is a special flying device, but I think you can only use that once. Guards AI has been improved drastically, safe spots are now not completely safe, gaurds can investigate them and possibly stick their sword inside your hiding spot and hurt you.
And you can also swim now, while AltaÃ¯r for some reason died on contact with water
I had AC for a bit, as glenwheeler said 'get pretty repetative though', I made it to the 3rd city (jerusalem?) then didn't play it again. I have wasted a lot of time on oblivion though with no intents or purposes. Far too much time.