I have set that the Permalink to be date, then post-title. Howver, I realise that there might be a problem with that, when the title is in Japanese. It seems to link properly, but the link is like “…%e6%97%a5%e6%9c%ac%e8…”. Just like in Wikipedia. Probably its not a problem as such, but the point of using the title as a permalink is so that people can get the idea of the post contents from it. I cheked out some other Japanese blogs that uses WordPress2.0 ME. They all uses post IDs, and not post title.
May be there is a solution by fiddling with .htaccess and/or PHP files, but not an option for me, with my very limited knowledge of them. Writing all post titles in English, even with the Japanese posts, is another idea, but I am sure there will be times when I want to write in Japanese. Using ID is another solution of course.
I will have to search through on this topic I think.