It's interesting, a lot of ideas in here are actually things which have already been implemented in FPS games in recent years; a tactical approach, non-deathmatch multiplayer modes, character customisation, jetpacks, sprinting, lack of cover-based shooting etc. Granted though, some of these have been done more than others and there are a lot of different ways to do them, statements like "give me a bunch of different ways to kill guys" are actually very vague and come with about a million different ways to implement. Likewise the idea of combining the best of modern FPSs with the best of old FPSs is a little vague and arguably flawed too. The modern FPSs have come about as a direct result of people taking old school FPSs, and adding new ideas to them. Additionally while there may be pieces of old FPS games worth incorporating into current FPSs the large majority of them aren't, on the whole these ideas don't exist anymore because better alternatives were found, if Duke Nukem Forever taught us anything it's that you can't release a game from the 90s in 2011 and for it to just work.
Additionally, the idea of realism for the sake of realism isn't something that ever works that well in practise, games tread a fine line between simulation and well... Games, but at their core they are the latter and when you start sacrificing gameplay for other components of the experience it doesn't usually end well. Oh, and if you are considering the idea of a console FPS where you hold about eight weapons at a time, consider that you'd have to do some pretty amazing (perhaps impossible) things with the control scheme to accommodate that. I could go on about regenerating health, cover, etc. but I think you get the idea.
I do like the ideas of less modern military games, a bajillion guns, more RPG elements and more colour though. In fact if there's one way you can say Halo still deviates from the norm in this day and age it's that it's actually a colourful series of games. I don't have any really strong ideas, I'm not a game designer, and frankly I think the FPS market could do with quietening down for a while but then that's just what everyone else has been saying for the past few years. If there's one thing we must remember though it's that, while innovation should always be encouraged, a game just being different by no means makes it good.