The first single from Bon Iver's eponymous second album, and it seems rather promising. Of course, as a Bon Iver lover I would be a little bias, so I'll trust you to make up your own minds. However, for now you can get Calgary for free on 4AD's website right here, along with dates of their UK/EU tour (oh so tempting!).
P.S. (Is it me, or is Bon Iver's website not running?)