I picked up Black Library's first 40k Audiobook, Heart of Rage by James Swallow. While it wasn't about my favorite chapter, it was a great story nontheless. It's a 'short story' about an encounter between the Blood Angels and a dormant Tyranid space hulk. Very 'Aliens'-esque if you like that sort of thing. Plenty of background music, sound effects and bolter fire in the background. Cool stuff.
My guess is with the re-release of Space Hulk just a couple of months away, the boys in marketing felt that it was the perfect time for the release of this CD.