The Japanese "regionals" are online and reward invites to their nationals which are held in person. On that subject...
Japanese Nationals Date!
Originally Posted by Fat Japan's 2012 VGC Site
That translates to "Japan Representative Determination Tournament". I'm not sure when this section was added to their website, but Japanese nationals look to be on June 10th(6月10日).
Original link is: http://ja.pokemon-gl.com/about/jc2012s/page1-1.html
-- Second section covers nationals. The location has yet to be announced, but it's the same place every year from what I've heard.