A Capcom rep has confirmed that Monster Hunter 4 Ultimate may not feature connectivity between East and West.
A comment from Capcom's Community Specialist Yuri noted how that Western players (presumably in both Europe/North America) will not be able to slay beasts online with folk in Japan. The two regions will be hosted on different servers, and wouldn't allow for inter-machine play.
A similar issue occurred with folk in North America and Europe in Monster Hunter 3 Ultimate, where a patch was required for servers to work together.
Monster Hunter 4 Ultimate will be released in Japan this fall, with North American and Europe to follow in early 2015.
Should Capcom open up the field for inter-region communication in Monster Hunter 4 Ultimate?