I know a ton of people will hate me for saying this, but I was a little disappointed seeing the appearance of Snake. Yes it could be nice to see a lot of 3rd party developers offering their franchises, but I did like the solid nintendo theme of the previous Smash titles.
On the other hand, if we do have 3rd party characters in the mix, then we migh as well go all out and throw in some other really good ones too and hopefully not just snake. It must be hard to do because there hasn't been a large number of memorable franchised characters in the past 10-15 years by 3rd party developers. Once you get Konami, Capcom, and Square-enix staple characters, are there really that much more?