First, we believe that using the Nintendo 3DS will allow us to offer new types of
expressions, game play action and enjoyment for the “Monster Hunter” series, which
has attracted a broader range of user segments. In addition, we selected this platform
with the goal of reaching a diverse spectrum of customer segments, including current
users of the “Monster Hunter” series as well as people who have portable game
consoles. - Capcom statement
This obviously has something to do with their plans for Monster Hunter 4 as well. This is a huge deal in Japan, and hopefully the rest of the world will catch on as well!