One possibility is Duodecim Prologus could be an English name for the upcoming PSP game Dissidia 012[duodecim]: Final Fantasy. However, Square Enix already announced the game for the West with the Japanese title as the official English title.
The registration date is also something to note. Square Enix already filed a trademark for [duodecim] with the brackets in Europe and North America. The Duodecim Prologus trademark comes more than a month later.
"Prologus" is Latin for prologue. Since Dissidia 012[duodecim]: Final Fantasy fills us in on the story before Dissidia: Final Fantasy could Duodecim Prologus be a prologue to 012?