Ya there already is a standalone version for Japan. And it hasn't really helped the game.
I'd say the main problem with MGO is that Konami refuses to integrated with the rest of the world and use the PSN. You have to sign up and register for a separate Konami ID, and on top of that a MGO ID. Not only is very annoying to have to do so, You cannot use your existing PSN friends list for match making etc. I don't know if this was KojiPro or Konami's idea. But it is pretty close minded dumb one.
I think they wanted to make lots of money on micro transactions and didn't want to pay Sony a commission for using their wallet system. Even from day one they were charging you extra if you wanted to more than 1 character slot on MGO. But unfortunately the game flopped so that back fired on them.
I say make the game a cheap fully PSN game like Warhawk. That seems to be the most successful financial model that MGO should be following.