Huge AC fan here, but I dislike this premise.
Assassins are not fucking pirates. If I get another Pirate of the Carribean 3 plot of pirates = awesome = assassins and law enforcement = bad = Templars, I'm going to puke. And of all settings and historical events, they didn't find anything better than the Carribean? I mean for fuck's sake you have the French Revolution begging for an AC game. How about the Far East?
And another male? We already had 5 games with a guy, enough already, I want a female assassin that's not relegated to a PS vista.
If it's the same writing team of AC3, then I have some faith. But I can't escape the feeling that they are doing all this to capitalize on AC3's naval missions and that's a horrible way to decide on a setting.