There isn't a whole of information at this point, except for a very brief 3 line article by Sponichi, but it appears as though Yusei Kikuchi will submit a letter of intent after the National Athletic Tournament and then decide what to do.
=== Update 9/15/2009 @ 8:16pm JST
Here are some quotes from his manager, Hiroshi Sasaki.
"He's going to submit his letter of intent and then listen to what some teams in the Majors have to say before making a decision."
"He has always wanted to go to the Majors, but I think going so soon will create some cause for concern. At this point, based on what he has said, it's a 50-50."
"He's still a minor so I'd like to hear a little more of how [MLB teams] bring up youngsters. I think whatever place allows him to grow the most is the best place for him to go to."
According to the article, 5-6 teams MLB teams have already visited the manager.