Unlike previous titles or other Square-Enix games. The European and American versions of XIII will be having a different song entirely for the theme of XIII (instead of the same melody with different lyrics sung by the same Artist)
In Japan they'll be listening to
Kimi ga Iru Kara (Because You're Here) sung by Sayuri Sugawara and composed by Masashi Hamauzu.
Europe and US are getting
My Hands by Leona Lewis.
Now personally I have nothing against Lewis or her work. And the song it self is actually nice. But I feel it doesn't fit the image FF presents and has presented in the past. Most FF songs have a orchestral feel to them, Lewis' songs doesn't have that. Now some representatives have explained the songs fits XIII's theme which obviously we'll have to wait and see for that.
Truthfully I think "My Hands" fits more at the end of a romance film about a women fulfilling her dream after dealing with a lot of hardships.