I am just curious because I would be shocked to hear that its one disk due to the amount of voice acting and content there is in this game. I mean I'm wagering its more if not double that of Oblivions in terms of the amount of dialogue, then couple that with all the dungeons, dragons, locations, cities, the amount of NPCS and of course all the items that are all modeled in 3D...

Go on tell me this game contains 3 DVDs for Xbox and not surprise me? : )

If it is just one disk I just have one question.

How?

Yes, one disk. It's the method of compression they used in their Creation Engine.

Todd Howard uses black magic as Adam Sessler proclaims

Only one disc and only 3.5GB on hardrive for a full install
John Carmack must be pissed, Rage is 22.5 GB and on three discs haha. Now that deserves a

Rage has a completely unique landscape, not the same textures copy&pasted all over the world.
Of cause this requires more space but is well invested and there is nothing to about.
If Bethesda had done the same with Skyrim, it would look even way more amazing.