I also liked the fact that Kojima kept saying that was all in-game. His translator kept looking at him like "ok we get it." He later explained that this was the last Metal Gear game that he is going to make and it wraps up the entire story.
In general, Sony at E3 impressed me a lot. They displayed mass amounts of games on all of there systems and made a point to state that they had 15 1st and 2nd party exclusives in the works for PS3. Games like Folklore, Heavenly Sword, Ratchet and Clank, Uncharted, and Little Big Planet were supposedly all playable at E3. The big thing for me is games in the future. They didn't even touch on Final Fantasy 13 or the God of War 3, though I think Square has there own press conference, which is promising.
Sony also had a few big announcements like the whole deal with NCSOFT and Unreal Tournament 3. And, lets not forget the new model PSP. In general, it was about games, games, and more games.