Just Snake, as far as I can tell. He is clearly hinting at Snake without flat out telling us it is Snake, nor is he leaving much room for predicting some other character because he isn't being vague and pointless. Either it's Snake, or a giant tease
Maybe he just started trolling now that he has gained some credibility with his dialog and music leaks?
But on the other hand, he's Canadian so I don't know..
Who is TheRumbalumba? Where did he come from? What does he want? Why am I aroused?
http://www.youtube.com/user/TheRumbalumba