DOOM - A Reboot or Re-telling?

DOOM was at Bethesda's E3 conference last night and many questions are still left un-answered. Is DOOM a reboot or re-telling? All that was really announced plot wise was that it was based on a U.A.C. facility on Mars and that multi-player would feature "maps from Hell." But this leaves me to wonder... will this be based on one of Mars' moons like Ultimate DOOM (original) or on the red planet itself like DOOM 3? Also... with this just being called "DOOM"... it seems quite likely that we'll see a reboot of DOOM II - Hell on Earth in years to follow.