God I don't even know where to start on this one. As amazing as this game will be, and it's definitely the #1 contender for my GOTY award, there are just so many things I wish it did different.
I want the ability to interact with everything again. I want to be able to steal pillows and candles and I want objects like plats and cups to actually be worth more than 0 gold because the Economy in Oblivion was extremely broken and unrealistic. I also want to be able to interact with Shelves and Cases and closets and mannequins to display armor, weapons, and objects in a way that makes them neat and organized without fear of bumpign them and everything going flying.
I want to be able to steal things and the whole world not magically know they're stolen so I can sell them to somebody other than my fence.
I want my Acrobatics and Agility Skills back. I also want my Crossbow, throwing knives, thorwing stars, halberds, pikes, etc... to come back.
I want less focus on realistic creatures and more on fantasy-like creatures like we had in Morrowind.
I want an Arena mode where you not only have ranks to rise, but you can challenge people to throughout the game and you can even keep encounter more NPCs with varying challenges and goodies to be collected.
This is just the tip of it. I'm sure there's more, but I'm doing something for more interesting in my other browser right now, so I'm not too worried about it at the moment.