What I think needs to be done in the next Socom is pretty drastic but would stand out from any other game. Right now Socom 2 is a highly addictive game but could add more spice if things were done to it.
A perfect tactical warfare game should require these basic needs, Variety of Weaponry selection and balance , Balanced Map Play and variety, Wide range of Player Models, Realistic recoil,damage,environmental damage, atmosphere, wounds, ( a real issue in warfare games today), some sort of currency involved is also a bonus ( ie. counter strike for pc... money money money! people love that when it is involved in a game) and also one of the biggest concerns is, A REASON TO PLAY is NEEDED! People don't play Diablo 2 for no reason, they want to achieve over others (power) and also has a fun factor and a desire to keep doing better.
Now if socom 2 has a reason, its getting up the ranks, but is not all that impressive and wonderous

. If socom 2 needs the reason to play, I say we should go up the ranks for a reason first of all, as in putting profiles and attributes for each player they use and make it permantley saved every time you go up a level, and so many levels until you hit your rank. Stats can include anything from reload time, to accuracy, to endurance, to stability, to stamina, and so on.. its endless.
That's one reason, but another is getting badges or specific medals on your character which would cause every soldier in the game to be unique from the battles of hell that they have been through. You should also have a wide range to choose from on what your char looks like, as in putting sunglasses on your char with face paint and an ace card on your helm, etc.
More stuff should be done, but these are only a few basic ideas. Please add more and we should be able to see is to come of the next socom. :D