I've learned to be realistic about my expectations. I'm totally open to various newschool features, but also know that changing the gameplay significantly would make it very un-Doom. Vehicular sections, iron sights, alternate firing modes, high-concept weapons, NPC interaction, mild plot points, portable inventory items and destructible areas are all elements I can deal with, and have wanted to see since I was an adolescent. It's regenerating health (unless it stops after a certain percentage), purely linear layouts, very slow player speed and a lack of demonic elements that would be absolute blasphemy; I'd like to think id is smart enough to avoid such changes.
Those leaked screenshots from a few years back represent what happens when you take a concept like "Hell on Earth," but don't have the imagination to modernize it. I think we can all imagine highly industrialized, futuristic cities in ruin, corrupted by a massive living demonic organism that eventually leads into Hell itself. What Doom 4 is going to come down to is artists who understand Doom's aesthetic and its influences (H.R. Giger, heavy metal, "Aliens," etc.).
I'd rather they not make Doom 4 a reimagination of Doom 2 because you can't make a game with design as outlandish as Doom 2's and get away with it in a modern game. If they made it a hyper-realistic Doom 2 questions such as "where are the cars and people?", "why are there wood and bricks everywhere?" would arise simply because of how realistic it would be. People wanted Hell on Earth and that's exactly what they got. Earth is one of the most boring places you could make Doom in and this is why they should avoid it. Alternatively, they could split the game into 6 hour episodes. One on Mars/Phobos, one on Earth and one in medieval Hell and hell factories made out of stolen UAC tech.
As for the features you mentioned, I fail to see why they couldn't be "fun" and "exciting" instead of just "tolerable". Alternate ammo and upgradable weapons could be a really good way to modernize the Doom formula while still maintaining its legacy. If Wolfenstein is what I think it is, then maybe Machinegames could make Doom 5 if Doom 4 bombs. Who knows, if Id can't get their shit together maybe they will even get to work on Doom 4.