Sent Pete Hines a quick tweet to check. Hopefully he'll clear it up for us. I agree it sounds beautiful, but given how much they were stressing a move into drums and rugged sounds... I'm not sure. Then again, they must have some slower tunes in there, and it is an amazing tune.
There probably won't be any drums all the time in the soundtracks.
The soundtracks must feel natural and pretty "calm" (not really the right word, but oh well), else you'll eventually get a headache. Your ears need to rest.
That's why Morrowind's soundtracks were so calm, while the main theme was so... epic.