According to Eurogamer (and most every other site reporting on QuakeCon 08), id has announced that a Doom II RPG is in the works.
After showing off Wolfenstein RPG ("We've put the action-packed fun of kicking Nazi butt onto cell-phone") for mobile phone for a few minutes, Id Mobile's Katherine Anna Kang announced the game.The first Doom RPG was simply amazing. I know that it personally helped me through some extremely boring classes during my Senior year.
Nothing was shown apart from a grinning Doomguy.