I agree with an earlier post, his stuff is kind of in a class of its own. Not much out there sounds similar.
Any suggestion would be a stretch, but two recommendations that iTunes popped out were Yeasayer and M83. I can kind of see that. Too Late by M83 and I Remember by Yeasayer, specifically.
Side note, if you have the chance, go see Jonsi in concert, it was a very moving show. I saw him in April and I was far more affected than I anticipated.