With a game like Smash Bros you'd think it would sell like.. more than a million on day 1 of its release. But, I'm gonna assume that a lot of people bought the game digitally because its just one of those games that you're gonna keep forever and never sell.
I think the majority of sales will come from the current install base. The problem for Nintendo right now isn't in making great games that people want to buy. It's making great games that make people want to buy their console who don't already own it.