I don't think it's out of the question to suppose that there might be a 3DS version. I mean, looking at the environments for the city, it kind of makes a lot of sense.

However, there are a few things that fly in the face of it:
- Nintendo hasn't really said that the game will be for 3DS; just DS.
- The American release date (Spring 2011) makes sense with the launch of 3DS because by then the 3DS will most likely be out or close to out, however the Japanese release of Black/White (September 18th, 2010) could be well before 3DS. Unless 3DS were to come out super early.
All in all, the above reasons aren't that strong, and if the 3DS is out
for holiday season by September 18th in Japan, then it is at least plausible. It actually wouldn't surprise me given that Nintendo recently stated that
changing the final design of the 3DS much. Who knows, but the inclusion of a feature the DSi can do as well isn't a clue at all because we know the 3DS is backwards compatible and has a front-facing camera.