Space Hulk does it’s thing in a gameplay demo from gamespot at GDC, it’s a little rough around the edges still, you’ll note a lack of movement animations but as the guy says during the video, its half way in production. It seems to mostly be a faithful recreation of the table top game, I recall reading there are some subtle changes to some of the rules to facilitate the video game conversion but otherwise it should be near enough.

I was interested to hear they plan on making alternative chapters available for the Terminator squads and apparently there are unlockable decorative adornments for your squads that survive multiple missions. Although he also says you get a separate squad per mission so I’m not sure how that works in practice, perhaps a global currency based on your performance rather than individual character success.