Okay, so as we all know, the Gamepad has Near Field Communication, which allows physical objects to communicate with the system to add new features and content to games. Sakurai has shown that he's quite fond of utilizing the capabilities of the consoles he's worked on recently, with the 3DS having AR card support, touch screen capabilities, a robust online system, etc.
Now, I think that the partnership with Namco Bandai could have more than a few meanings behind it. Bandai is well-known for making action figures and the like, and I think this could be combined with the NFC in a crucial way.
Smash Bros. has been largely focused on trophies (and toys) ever since its inception, so what better way to provide DLC than through literal trophies? Place them on the NFC and download an all-new character to the Wii U, releasing waves (or even just one) throughout the entire lifetime of the game and the system. But that's not all. What about trophies in different costumes that could add new appearances to your characters in game? With Bandai distributing, there's no doubt of their availability.
I think this could be a clever way to not only prolong the life of the title, but also cause kids to go into a Skylander's like frenzy over the concept. Plus, come on- wouldn't you like to have a nice little collection of Smash Bros. trophies on your shelf?
Of course, I'm not saying the initial roster should be nerfed in any way- there should be a sizable amount of content in the game at release, as Nintendo has stood by with all of their titles in regards to DLC (or lack thereof- I'm including games like Fire Emblem and NSMB2 as reference points).