Then I guess sooner or later, we're bound to see Master Chief, Flynn Taggart, Crash Bandicoot, Spyro, Diddy Kong, Darth Vader, Toad, K. Rool, Tony Hawk, Sonic, Eggman, Luke Skywalker, Dr. Wright, ..., and Spiderman in a Smash Bros. game.
Nintendo isn't exactly hurting for characters from their own games. They may have to start seriously digging in the 3rd party poll sometime in the future, but this could be years from now. It's bound to happen eventually, but that eventually may not come some time from now. Or, they may just opt to go ahead and get as many 3rd party characters as they can.