Granted, I've only seen a few screens, but I'd be a lot happier if they chose to show some more variety and put my fears to rest...
At first I also thought the graphics were not far off from Oblivion, but then I checked some Ob screens and went wow, big difference. Also there is one Skyrim screen of a very tall cliff with 2 waterfalls reminded me of something out of Gothic 3 which has the best designed(artistically) open would of the sandbox rpgs I have played(OB,MW,FO,Risen,TwoWorlds 2 & Gothic 3). Gothic 3's world is full of cliffs, rivers,waterfalls and other points of interest, vanilla OB lacked this. But that one pic of Skyrim with the waterfalls(and water flows now!) is better than anything from Oblivion from a design standpoint.