I don't think they could do anything official, but I'm sure that it'd be way easy to create for yourself. If you use the Zombie creation rules from AFMBE for creating "The Flood", create a couple of racial packages (ala Terra Primate or Beyond Human) for the Covenant, and scope out some of the fan-sites for seriously cool SF weaponry, you'd be well away!!

Maybe a HALO-esque setting could be one Deadworld in the much anticipated and oft-delayed "Space Zombies" books (that originally had the title "Zomb()es"(like Aliens - the movie)...

Dave (DFC) - who's still wading through the Library level, managed to get to the next level and beyond on co-operative play... then discovered you couldn't save it... ARSE!