I don't know about others, but I have a feeling that I would not be disappointed this time, or more accurately I will be disappointed, because I have a lot of great ideas for a great RPG but few of them would be in Skyrim.
But on the whole, I would feel that they have done their best, and will be content with it, because they would not repeat their glaring mistakes with Oblivion, and without those mistakes, a BGS game is equivalent with a masterpiece.
And I know and I am resigned about the fact that in the wealth of lore and complexity of dialogs and quests, none will reach the Morrowind level, because voiced dialogs will prevent that, but it would not result in Skyrim not being a masterpiece.
I can't say I that I was disappointed when Oblivion was released, it was just in far contrast to what Morrowind represented to me. Oblivion was a great game in it's own right, but Morrowind was a much better game in regards to the depth of story, variability of landscape and NPC's, and such a rich backstory. Oblivion was very pretty to look at, and had some cool quests, but it just didn't deliver the same experience as Morrowind did. So while Oblivion was not a disappointment, it was a degredation in game quality due to the constraints presented to the design team (HW uncertainties, etc.,).
With the amount of time they have spent on PC's and consoles (Oblivion, Fallout 3/NV etc.,), I'm sure Skyrim will be leaps and bounds over what Oblivion was.
I just hope the UI isn't as bad as Oblivion's was, and the consenus seems to be the same