The official website for Vantage Master Portable official site is open but there's not much on it yet besides a few introductory profiles of the Masters you can choose to play as and the fire type Natial units that will be at your disposal. There's also some PC / PSP wallpapers and XMB themes for download.
The story differs from character to character but, there should be a main story. I'm guessing they're saving it for when the trailer's ready. Wonder what this one will be like... Too bad Makoto Shinkai and Tenmon aren't working for Falcom anymore!