Well, as you said, Mr. Kojima is not taking part in the making of these two new PSP MGS games. They are both based on the concepts of multi-player co-op. The idea of this game-play type was made by the same person who made the concept of focusing on multi-player for Resident Evil 5. The game doesn't really focus too much on the story as the others. Though the objective is still generally the same, covert ops and taking down metal gears. However, it does take a little of a nasty turn. Like RE5 on professional mode, there are parts and difficulties that no matter how hard you try, you need a competent human partner. I personally find that to be ridiculous, but that is just my narrow-minded point of view for two reasons.
1) You're lucky to find a person with a psp, and even more lucky if they share the same game interest and have the same game.
2) Most players in the world are either incompetent, or they can't' work in teams if their lives depended on it.