I was pointed to this by someone else, and I am quite curious whether it was a coincidence, something Jeremy Soule did on his own, or a company decision. Any way put, hearing it hyped me up and increased my excitement over the new game:

http://www.youtube.com/watch?v=2H7kjsRQG-k

What do you mean a coincidence? And I believe the maker of that epic piece actually posts here.

A coincidence in that each piece wasn't intentionally meant to go together, but the do perfectly anyway. Stranger things have happened. That video has been up for a while, but I hadn't heard it before. So I was curious, hence my registering an account here to ask.

They're all essentially the same theme, that's why they go together. It's also important to note that the Morrowind theme had its speed increased by quite a lot.

They are different renditions of the same theme. It follows naturally that they would fit together.

Since it's done in the same series by the same composer, no it's not a coincide. When composers use the same theme over, it's usually done intentional.

Well they don't really fit together. Mrpantsleeves had to change both the speed and key of the pieces to fit togethor. If you listen to the themes separately you can see he changed them.