In their financial statement for the first half of their 2006 fisical year, Ubisoft have mentioned an as of yet unknown game that will be announced for the Xbox 360 system.
Speculation could set in that it is one of the four next generation titles that Ubisoft Montreal is not yet ready to talk about. Otherwise, no other information on the game has been made available as of yet.
The Advanced Media Network will provide further information on the title as it comes.