While this is not a whole lot yet to see, I just love the codex covers we have seen since the onset of 6th edition. Very powerful imagery, and the Space Wolf one will be no exception. Here is a brief (I wish I had more on this) description of it.
The above pictures is not the codex cover, and is from the teaser video Games Workshop released this morning.
Please remember that this is a rumor, from a very good source.
via an anonymous source on Faeit 212
Codex cover shows an Warrior with Bolter and an primitive looking power sword.