We'll see what ioi puts up tommorow, but 300k isn't bad if it is the number.
We've already seen Smash isn't as big in the Americas as Japan though.
Japan = 130 million, USA+Canada alone = 330 million
Most non-pirated software in the Americas is from USA+Canada...so a 2.5x factor is roughly in order.
Smash at a 842k launch week in Japan could have meant Smash at 2100k in the Americas week one...but it was about 1600k launch week, about 20% shy of 2.5x Japan's opening.
Looking at it as an attach rate though is pretty interesting:
843k/5204k in Japan
1577k/9796k in the Americas
16% attach ratio both launch weeks. The fact that it is likely to drop faster in the Americas suggests that the title has wider appeal in Japan, which makes sense since there is far less Xbox 360 interest in Japan, and Wii is more dominant in Japan than it is in the Americas.
I wouldn't be surprised if the game ends up selling nearly the same amount weekly in the Americas and Japan in five or six weeks.