Well, there go our dreams for a PokéMMO; Nintendo president Satoru Iwata has confirmed that Nintendo has no interest in developing an MMO at this time, possibly putting to rest the rumor of a massively multiplayer version of Animal Crossing, as well as any hope for Nintendo further broadening their online offerings.
Specifically, Iwata stated that Nintendo would only pursue MMO development if the title could appeal to people of all ages, from "5 to 95." Looking at Second Life, Iwata belives that MMOs aren't yet accessible to people without a fair degree of computer literacy, and that Nintendo would want to successfully cross that bridge before considering going the MMO route.
The answer bums us out a bit, but at least it shows that Nintendo isn't entirely close-minded to the possibility. Maybe we'll someday get a PokéMMO after all?