So here is how it can be
Wolfenstien - > WW2 setting with Nazi demons/zombies
Doom -> Futuristic setting Demons
Quake -> Medieval setting with demons
Rage -> Post apocalyptic setting with mutants
It's all demons and mutants may be aliens in the mix for the new doom or rage
As far as MP is concerned. They should really amp up the "PRO" factor like in Quake 3. Make sure that every game of their is of E-Sport quality and that the dedicated get the rewards they deserve, not in terms of perks
Here is what the MP should be like
Doom -> not too sure, they can still create something unique because the first two were too old and the MP in the third one was an after thought
Quake -> Fast pace DM CTF CA DUEL etc etc, like quake live. This is QUAKE
Wolfenstein -> Enemy territory style gameplay
Rage -> Again something unique can be created.
My point is don't mix the styles like don't tack on Quake live like gameplay onto the new Doom or Rage give them a new style. Where as the old ones are concerned, don't try to make them unique as they already have their own identity. Quake gameplay shouldn't be mixed with that of wolfenstein.
This way each franchise maintains it's SP and MP identity and non id fans don't think of every id game as being QUAKE 3.
