Forgeworld -- 40K Expansion (via Warseer)

It looks like Forgeworld has a new rule set for a 40K expansion in the works; Zone Mortalis;  for fighting in enclosed spaces.  Here are the links:

Warseer Thread
PDF
Forgeworld

It includes some of the rules for Boarding Actions from IA-9 which are very cool and adds a few new wrinkles for fighting in Underhive areas, caves such as Cave-ins, Tremors and Quakes.   Also added are rules for Reaction Fire -- reactive fire to assaults -- very cool stuff.  Also they've added some elements of Space Hulk such as blips which should make life even more interesting... Now if only I had a good piece of terrain....