I've been trying to keep updated on the release of this film, and according to a user on IMDB (who's said he researched), Square is currently having distributing issues with Columbia Pictures. I don't know if this info is legit (since the user never provided links to his info), but I'm just taking his word for it.
Amazon.com has the release date set to 2010, but that's only because they have no release date. Places such as Walmart, Best Buy, and video game shops have different release dates ranging from Feb, March, April, and June. But really, they don't know when the release date is because one hasn't even been set.I did a little research and I found out the reason why the movie has been delayed again. Apparently, when Square signed the contract for Spirits Within, the contract included at least three more Final Fantasy movies. So when the time came to distribute Advent Children in the US, Columbia Pictures threw a fit about it and brought the contract out to show Square. Now both Square and Columbia are in a legal debate since Columbia is refusing to distribute Advent Children after all the money they lost on Spirits Within. It's possible that the two companies could be in talks for months before a descision is reached and Nomura himself has said that the US will have Kingdom Hearts II before Advent Children, since KH2 is being more highly anticipated than Advent Children. So, please, stop blaming Square and write your letters to Columbia Pictures. There's another rumor that if Columbia loses the legal battle than Advent Children may get a small US theatrical release.
I'm not sure if the English recording has been finished yet, or if Square will go through with that once the dispute is over with Columbia.