A post about Nintendo over at the Wall Street Journal ended up revealing something interesting. It looks like Tomodachi Collection, AKA Friend Collection, is coming to the 3DS in the west at some point.
The final paragraph in the article talks about Nintendo deciding "what can be kept and what needs to be scrapped for its overseas launch of 'Tomodachi Collection' … a 3DS life simulation game in which Miis from consoles can interact with one another and develop via mundane activities, such as exchanging food and clothing."
Gaming site Tiny Cartridge followed up with Nintendo of America's PR team, who said there was nothing to announce at this time. The series is a big hit in Japan, though, and it sounds like Nintendo is working on tweaking it for an eventual western release.