Finish the fight.
"What can I say about the ending ... it's the final chapter of Solid Snake, no joke about it. There's no smoke and mirrors, no jack in the box trick, this is the final chapter in his life, and in his story," Ryan Payton from Kojima Productions says in his revealing Metal Gear Solid 4 interview. In addition to promising a fulfilling end to the MGS saga, there are hints at unannounced gameplay modes (vehicles, perhaps?).
Most surprisingly is the differentiation between both the English and Japanese versions of the game. "It's going to be harder than the Japanese version, I can say that right now." The main reason for the difficulty change? The new FPS controls: "That over the shoulder view is going to be, I hope, the focal point. I want to make that the default setting." Honestly, we like it better that way. Make sure you read the rest of the Joystiq interview for more.