No news yet. Koei is currently in the midst of promoting Dynasty Warriors NEXT for the Vita, and Ninja Giaden 3 (neither of which have official release dates) they aren't likely to even begin promotion on OP until after those are released. It was only just ANNOUNCED at a recent gaming show, there's usually 1-2 years of production after initial convention teaser demo before the final product comes out.
There isn't even a starting roster of characters announced yet, the odds of a spring release, even in Japan, are unlikely. Early summer-late fall is a much more likely bet, that would follow the traditional Koei release schedule more closely. (They generally lead up to release with about 5 months of magazine ads that reveal a character or two at a time)
And if it is to get a stateside release, it won't be for another 5 or 6 months after the Japanese release.
So even if it came out in Japan this March, we wouldn't be getting it stateside until October, if at all. Don't expect it before late 2012.
Please don't bump this thread *asking* for news, that just gets people excited needlessly. When there IS news, this forum will be one of the first places to jump on it and announce it.