The official site is now up.
Called "Super Movie SD Gundam Sangokuden Brave Batter Warriors". The characters are illustrated in 3D it seems.
Premiering on February 27th 2010.
With the complexity of the story and the vast number of characters, I doubt that one movie is sufficient to tell the entire story. It's very likely that the sequels are already under discussion now. ^^
Images are from the official site.
