[Image from 41 Strange]
Push Dustin and New WabiSabi just dropped a bomb on the Smash community and the speculation train is already running at a fever pitch. According to a now-deleted listing on Nintendo UK's website, the next Smash DLC carries a copyright from SNK, creators of the Neo Geo console and developers of Ikari Warriors, Metal Slug, King of Fighters and other iconic franchises.
It would add up that SNK would eventually get representation in Smash. The company is arguably as historically significant as Sega, Square-Enix, and Konami, especially in the arcade sector, where the were among the world's most successful publishers throughout the 80s and 90s. That's why I'm guessing that if the next Smash character is from SNK, it will be Marco from Metal Slug (with Ralph/Clark from Ikari Warriors as an alt costume). Terry Bogard, or better yet, a whole 3-way tag team from KoF, would be a fantastic choice too, but when it comes to representing the kinds of games that are quintessentially SNK, the tank-hopping, cartoon military action of Metal Slug/Ikari Warriors makes more sense.
I also wouldn't kick Bub and Bob from Bubble Bobble out of my Smash bed, but since they are owned by Taito, and only licenced to SNK for Neo Geo titles, their chances are slim (for now).