I haven't been able to find anything solid about this, other than 'mod tools will be bundled on release'... but is it just ingame variable changing or is there an editor, akin to GECK, for world modding and quest addition etc?
Thanks.
Judging from the modding communities of past ID Software games, I would say yes, and it will probably out-match Fallout. The Fallout community is sort of starting to die down (when's the last time a huge mod was released for Fallout 3? Or even New Vegas for that matter) but Quake, Doom and even Wolfenstein still have modding communities today.
That is, of course, if ID can fix the myriad of tech problems people are having right now. I honestly don't envy ID in their position right now, their first new IP since Quake and its plagued with many technical issues. I'm sure that until they get it fixed to at least a playable state (without the popping) that everyone there will be pulling all-nighters. I would think they would be though...if I was in charge of ID and I found out about these problems I'd be like "okay, lock the doors, nobody leaves until we get this fixed!"