It has finally happened. This alone makes the PS Vita worth buying.
Konami put together a nice video of all the new touch features added to the Vita edition of the game.
Exclusively for the PS3 edition of the game is the feature of transferring your game save from your PS3 to your PS Vita, and vice versa, so you may continue where you left off when playing either version.
For more info on the game, and the series, visit metalgearsolid.com