Over 2.8 million copies to be precise. That's a lot of units.
It is worth noting that while the game came out in Australia this Saturday, it has been available in other regions for a fair amount of time. It came out in Japan on September 13, for example. And boy did it do some serious numbers in Japan.
That being said, it does appear that — surprise surprise — Super Smash Bros. on the 3DS has been an overwhelming success.
Considering the amount of 3DS consoles in the wild, it's almost to be expected. I'll be interested to see how well the Wii U version does in comparison, considering how poorly the console has sold in general. Will Super Smash Bros. actually shift Wii Us in the way, say, Mario Kart 8 did? It's difficult to say at this point. I wonder if releasing the 3DS version in advance will actually be detrimental to sales of the Wii U version. Surely there'll be people out there who don't want to buy two copies of a similar game in such close proximity.