Capcom has confirmed that Monster Hunter 3 Ultimate is coming to the 3DS in North America and Europe during March 2013. The touchscreen “allows players to quickly access in-game books, weapons, field maps and mini games”, and:

Taking advantage of the portability of the 3DS, players can exchange their guild card that contains all of their hunter’s information with other players via StreetPass.

I’m guessing this is the Monster Hunter announcement we’ve all been wanting. The game is also coming to Wii U, which is neat.