How do you know it's the final version and not the demo version? From what I have heard the leaked version had several horrendous glitches that would never get passed the development stage. Bethesda is better than that, that is all the proof I need, unless you can prove otherwise.
We know its the final Xbox copy. We're not going to have a debate on the workings of the scene on Bethesda's forums, but release groups are extremely diligent about how they tag these things. This was leaked after the game went gold, it's a press copy, it's the real thing.
As for glitches, they happen in new releases, and no, Bethesda is not above that reality. They give good post release support, and will probably patch most of the issues, but there will be some 'horrendous glitches' as always at first.