Capcom is developing Monster Hunter 4. This was revealed today at the Nintendo 3DS Conference as a 3DS title.
The game's debut trailer was shown. MH4 currently does not have a release date.
More photos, courtesy of Famitsu, in the link below.
<img src="http://cache.gawkerassets.com/assets/images/kotaku/2011/09/av3mdxjjig173uao2bjhl3vg1h7374lt.jpg" width="640" height="425" />