It seems that Project Rainfall may have justified itself yet again! Executive Vice President Ken Berry revealed that the RPG "has become our most successful title to date." XSEED declined to offer specific sales numbers. I'm not entirely sure what "most successful" means, but hopefully it will open up a good relationship between Nintendo and XSEED and perhaps lead to more future collaborations.
The Last Story is also getting a reprint, and price drop to $29.99.
@Hinph I read some article once that basically claimed that Japanese corporate culture doesn't like to promote individuals. Although certainly there are some exceptions, Kojima, for instance, tends to get his name prominently placed on his games, and Suda51 definitely gets his dues.
Of course, none of this explains why more Western developers aren't doing it.