Well hopefully if they do DLC for Smash Bros. (though they said they wouldn't in an interview) hopefully it's like the Mario Kart DLC which had 8 maps and a few characters.
I found Mario Kart 8's DLC to be both wonderful and concerning. To my knowledge, a large number of DLC packs aren't profitable (or necessarily have high attach rates except for games like Skyrim). That was the reasoning for DLC being unreasonably priced for the amount of content you got, and here Nintendo released something good and well priced. I can only wonder how that's working out for them financially.
(My hats off to Nintendo for being a good sport of course).