Sorry to tell you this, but it's not a new FF7 game.
The good news is, it's an FF7 CGI movie. There's a trailer floating around on the net that you should be able to find with some searching.
It takes place 2 years after the end of FF7. Sephiroth is back in someway, perhaps by influencing some children and infusing them with his power or something. The trailer shows cloud fighting some sepheroth look alike kids that are giving him a run for his money.
Cloud and the gang is back, the CG is great as always. Tifa kicks butt in this one scene in the trailer. I'm not sure how it will be released, probably a DVD here in the US (hence the march 14th release?)
Here's the japanese website.http://www.square-enix.co.jp/dvd/ff7ac/
ANd what looks like a knowledgeable fansite:http://www.adventchildren.net/
Another bit of good news is that Square, or at least some ranking staff, is really planning an FF7 sequel game. Something about it being set several years after the movie, but you know how secretive Square is.
By the way, where did you see the 3/14 release date? I've been looking forward to this, and if there's going to be a release, I want to get it day one.