Ubisoft recently posted up over Twitter, with nothing other than the link and a #RUSE tag.
For those who can't be bothered to click the link, it's an image of the Steam logo, with 15-7 written just below it.
What could it be? My money is it being the that Ubisoft were thinking about doing for fans after the game had to be till September. The first public beta was also held over Steam, so this would make sense. k
Still, we'll have to wait and see though, as Ubi's Pete Closs (in that coy manner PR's do) simply said "I can neither confirm nor deny. It could all be a RUSE. ;)"