I hate how the current game hasn't even been out a month and now we're getting information about the next one already. This only means that they already started working on 'AC Victory' before Unity was even released.
Releasing the game on a yearly basis didn't work out for CoD too well either, and they even used to have 2 different companies working on it, so they had 2 years each.
Why can't they just do what Rockstar does? Make a proper game; polish it up nicely, spend the next 2 years updating it before you even start working intensively on the next thing? They are literally the only ones that can get away with releasing a trailer for GTA V in 2011, and then releasing the game in 2013 just because everyone knows that it'll be good.