Originally posted by cooldude6681:
The Portal 2 team contacted The National and asked them to write a song for the game.
As for the tune you linked to, I like it, despite the fact that it reminded me of the song "My Heart Will Go On"
from The Titanic. It's a good beat, and could easily be adapted (or sampled, even) for a range of applications. I could see it being used in a cutscene (probably for an RPG), or as the basis for a dance mix in a club.
Based on the comments, and the other videos in that user's channel, I would venture a guess to say that ra9ooo is the artist who made it.