Almost everyone and their mother was against Snake because he was the "Sony" guy.
Well, maybe not "against," but people still constantly say he has no chance because of Konami.
Really though, this just proves more than ever that anyone who says Snake has no chance can go eat it.
My issues with Snake had nothing to do with Sony and everything to do with Konami. I still also always believed he had a chance, just not a great one.
The difference between the two situations is fairly self evident. All things considered equal (taking vet status out of the equation in particular) Banjo has a stronger fan base among Nintendo fans (I would personally take Snake over him any day of the week, but I am in the minority) and was thought to have no chance. Now he, a character many still think of as a Nintendo icon, has at least SOME chance. Hope is a powerful thing. People are going to hold onto that hope until the very end.
Snake still has a better chance than Banjo barring some monumental support and a complicated PR agreement between Microsoft and Nintendo (seriously, why would Nintendo agree to this unless MS included a Samus skin in the next Halo or something? Even then, a stunt like that would benefit MS more than Nintendo.) That being said, I still doubt Snake's inclusion as DLC at the moment.