Every dungeon in Oblivion was unique...?
That depends on your definition of "unique". While each dungeon in Oblivion technically might be unique in that the exact same layout has not been used twice, but it really didn't FEEL unique, and that's what's important, really. But from what I've seen on these forums, it sounds like Skyrim will do much better in this regard, how much better, I don't know, but if they can deliver on that promise, I'll be pleased. Because the lack of variety in both Oblivion's landscapes and dungeons was always one unfortunate aspect of the game for me, if Skyrim can do better, then at least in one respect of the game, it will deliver what I'd have asked for.