Genre: post rock, ambient
This isn't really post rock because it has quite a few lyrics, but it sounds very much like a slightly more complicated Caspian or This Will Destroy You. Tracks 2 and 4 are realllly excellent. I highly recommend their second CD as well, "The Sentinel," which is a little less ambient and more post rock-y.
EDIT: Here's "The Sentinel" too, by request: