Recently, the March 2010 issue of Famitsu magazine was released in Japan. This article features Kingdom Hearts Birth by Sleep. Although this magazine has not yet surfaced online, many key details from the article have, as well as a couple of partial scans. Firstly, the article is known to contain an interview with the series' director, Tetsuya Nomura. 2channel have typed up a script of this interview, and Kingdom Hearts Insider have translated it, which can be read below.
Nomura: KH:coded will be reaching it's climax soon. Both "coded" and "Birth by Sleep" have deep connections, and these two are also connected with the story that comes after KHII.
-- And what about connections to III?
Nomura: Well I don't know yet. There has been quite a lot of story told up to this point, it might be better if we take the time to lay it all out and explain it clearly. But how that will turn out I can't quite say yet.
-- How is development going?
Nomura: Right now we’re in the final stages of development, making revisions to the text and such. This time the story has many difficult parts and we’re working to make it flow better.
-- In which order do you suggest playing the scenarios?
Nomura: As far as the story goes, the best would probably be Terra -> Ven -> Aqua ->, but Ven will probably be the easiest.
-- That star fragment was shining, wasn’t it.
Nomura: This is something the King uses to go to other worlds. At this time they are called star fragments, but later they are called Gummi blocks, the parts that are used on Gummi ships.
-- How many years before the first KH is this story set?
Nomura: 9 to 10 years before.
-- And we’ll get to see Organization when they were humans...
Nomura: Well, Xigbar has said before that he has met with keyblade wielders. So of course many members of the Organization will be appearing. Even number VIII, Axel.
-- This time you’ve chosen a new guest character, Zack. Why did you choose him?
Nomura: Because this game is set in the past, we wanted to include a character that was from the past in an FF game as well. So we chose him. He is slightly older than Ven, and wants to become a hero. He is at Olympus to ask Phil to let him be an apprentice.
-- Will any other FF characters be appearing?
Nomura: No, only Zack. We wanted to show Cloud and Leon’s past as well, but we felt if we added too many characters it would just get confusing, so we left it this time.
-- Will we be able to fight against Master Xehanort and Vanitas?
Nomura: You’ll have to wait and see (laugh) Also, each character will have a different final boss. It will be interesting to see who will fight who.
-- You said that there will be a secret movie this time...
Nomura: I think the effect the story will have will be different if you watch the secret movie, rather than just the ending. I can’t say exactly what, but the secret movie will not only be connected to the next game, but will go over the whole story.
-- What will be the requirements to see the movie?
Nomura: As always, there will be lots of them. There will be three different difficulty levels to chose from, but depending on which one you chose the requirements become easier. You can’t see it at the easiest level.
Lastly, partial scans have appeared on 2channel. These scans reveal Saïx's original name, Ïsa, and confirm that both Ïsa and Lea will be included as residents of Radiant Garden. This can be seen here and here.