When asked whether or not Super Smash Bros. for Nintendo Wii U and 3DS will add new characters, stages, or other content as downloadable paid-for add-ons, game designer Masahiro Sakurai said that the company would rather add what couldn't have been included by the game's launch.
I understand that DLC could add a lot to the appeal of Smash Bros., and I appreciate that a major part of the excitement for these games come from which characters will appear in the roster, so I think fans could really enjoy DLC that could keep this excitement going. However, I think there might be criticism that we are cutting up content to sell characters one by one, or that we are adding things later that should have been there from the start.
Sakurai points to the level of investment needed to create, balance, and playtest a single character in Super Smash Bros. for Wii U as reason enough not to add new characters via DLC, though that doesn't mean add-on content is out of the questions altogether.
However, what I can say now about paid DLC is that we aren't working on anything at the moment. We've put all our efforts into making the actual game. Creating DLC would involve large additional costs and require the involvement of a lot of people. I can't yet give you an answer about whether the price would justify the costs and criticisms mentioned above.
When asked about new modes for amiibo fighters and leaderboards for the Home Run Challenge, Sakurai also said that decisions hadn't been made as to how to extend the game. Be sure to read our full 5/5 review of Super Smash Bros. for Wii U here.