Capcom made two big announcements in the last two weeks, and both will trickle down into Monster Hunter 4 Ultimate next year.
As you can see in the trailers above and below, characters from Capcom's Street Fighter 2 (above) and the Devil May Cry series (below) will join the roster of monster hungry travelers. Monster Hunter 4 Ultimate is slated for an "early 2015" release on Nintendo 3DS. At that point, you'll also be able to play as Link, Mega Man and Samus.
For more on Capcom's recent announcements, be sure to read Polygon's coverage of Street Fighter 5 and the two Devil May Cry games coming to PlayStation 4 and Xbox One.