Who else was taken by surprise back in E3 2007 when Solid Snake was announced for Smash Bros Brawl? Well, be prepared to be surprised even more; the person responsible for the inclusion isn't Hideo Kojima, the creator of Metal Gear, but his son. Apparently he thought this was a good idea...and probably didn't want to see his son go disappointed.
“My child likes Super Smash Bros., so we play it a lot together. And he told me that there’s no character that you made in that game.”Source
“As you know, we did make Twin Snakes, but generally speaking, there hasn’t been a lot of Metal Gear on Nintendo platforms. So from that perspective, I thought it was a good way to expose younger people to this character, Snake,”