User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-4911512-20130210225252/@comment-5489419-20130211081456

Wii U has online, as confirmed above. 3DS, however, does not have online capabilities--only local multiplayer capabilities. The 3DS can connect to the Wii U and play with the Wii U player simultaneously. The Wii U cannot take the connected 3DS player online with them.