I disagree to these points. The 3DS is the current generation handheld system, so of course Nintendo would be pushing for games to be developed on it. Given the steady rise in sales of 3DS consoles, Pokémon could definitely give the 3DS some extra (and at the time of Japanese release, needed) sales momentum.
Given the sales rate of Animal Crossing, there's no better time to get to releasing a Pokémon game to ride the 3DS sales momentum. And really? People who want Pokémon and don't have a 3DS? They'll get one. As we type messages back and forth, the folks at GameFreak are inevitably midway in the development of a 3DS Pokémon title. Obviously it wasn't going to be Black 2 and White 2.
And anyway Most Likely a Pokemon Title May have been In development from the start of the 3DS LifeSpan
Just they Haven't told us anything because it would ruin the surprise