I was honestly thinking the same thing as Longo.
The "bionic arm" in my opinion looks like a reference to the wrist blade weapon found in the first game. It will probably come into play once again (considering it was a sort of "signature weapon" so to speak), perhaps... newly designed maybe? Strangely I also noticed that on the hand of the "bionic" arm, the wedding finger (I might be wrong on which finger exactly but you know - the finger that is cut off) looks like it isn't cut off, since the skeletal hand with the blade over it has five perfectly long, normal fingers.
The constant hazing suggests the futuristic element to the game. I'm suspecting that once again the main story will be in the past, being seen through the eyes of someone in the future/present time using the Animus device as seen in the first game. Would it be Desmond Miles once again, or someone else?
I'm guessing with the whole... Leonardo da Vinci thing going on, the main plot will be set in another time line, set further in the future (but still the past). As Longo said, the 15th-16th century? If this is the case, then players will probably be playing as a new character and not Altaïr and more importantly, the location of the game would probably be elsewhere too. Somewhere in Europe and not the Middle East?
That wing also has some possible suggestion. It could be suggesting that (again, as Longo said) the game will be allowing the player to take advantage of the technology found in such time line with fictional uses (for example... considering the gliding wing, perhaps the player may be able to glide with some sort of winged device?). Altaïr's sorta, "symbol" was an eagle and I noticed that the wing in the trailer looked like a bat's wing, so perhaps if there is a new character... his/her "symbol" could be a bat (no, not Batman)? Maybe if it's a bat, this could imply game play that takes place during the night, or perhaps entirely in night (since Assassin's Creed, the first one was always set with the sun up... right? I forgot).
I went completely nerdo on trying to analyze the trailer, but such influence comes from GameTrailers.com and their methods of analyzing trailers. Hopefully they'll release a trailer analysis soon.