Well, after 4 hours playing, I am able to form an opinion on Skyrim:
It's bloody brilliant.
I have only done a few of the quests and explored 1 dungeon. That was 4 hours of content, and I don't feel as though I have even scratched the surface of what it has to offer. I can see myself spending hundreds of hours on this game, trying to complete all of the quests, side quests, achievements, maxing out my skills and much more.
I am very impressed.
By the way, to give you an idea of how good this game is... I normally have a very good sense of time, but just now I looked at my phone, thinking it would be about 1.30am. It was 4.20am.