I think that the pirate theme (even in its most dark representations, like in the original "Treasure Island") deserved a good game, finally.
Im not too sure if this is to be the one, I think that the douchebag decision of mixing "Pirates" to the "Assassin brand" is a bad idea... It's like apple and oranges. The [secret] Assassin sign on the Jolly Roger? Dont make me laugh...
As far as the trailer goes, I find it very strange that is Blackbeard, famous for being so cruel, fierce and flamboyant (always wanting to be the center of attention), who's basically telling you, dont hang out with me, hang out with this other dude, who is ten times cooler than me... Not a fan of those inconsistencies..,
and the bad writing ["Amongst the gentlemen of fortune, sailing in the West Indies...he's ranked amongst the most clever"].
A couple of good things from the trailer and tidbits of info:
1)They finally figured out that they need a charaismatic, swashbuckling character to drive the players attention. Instead of all those stoic, boring ones.
2) NO DESMOND. "Future" settting has a very minor role, aparently.
3)Sidequesting will be meaningful, as in searching for shipwrecks full of treasure (like in Assassin's Creed 2, with the catacombs' raids).
4)Naval battles seem to take a big part of the game, which is great.
Things I dont like... Rushed games. And this Im sure is one of those, which will suffer for it.