I never really thought 40k could work as a card game, however I think FFG has done a really great job. Obviously I haven't played it yet, but all of the promo resources look great. Also, you can view a full demo of the game here:
https://www.youtube.com/watch?v=9GfT4LGZU4w
Some pics:
You can see other expansions here:
http://www.fantasyflightgames.com/edge_minisite.asp?eidm=261
Anyway, onto the Mechanics. My first impression was that it was just another card bashing game, but I was wrong. The planet system is pretty cool, and definitely adds a unique sense of strategy to the game. Deployment is great as well, alternative placement means balance was definitely thought of. Combat I am still not completely sure of, but I think once I get my hands on it, it will be fine.
I think this might be a great catalyst to kickstart me back into the 40k world....hopefully!