While not divulging much about the trailer, Ubisoft gave a hint to the story of the game. You play as one of the survivors of Oceanic Flight 815. According to the description provided by IGN, "you'll have to try and unravel the mysteries of the island while dealing with unsettled business in your past." Ubisoft said that you will also interact with familiar characters and battle Ol' Smokey.
If we're playing an unknown character from the original crash, we're kind of worried about how the game will progress in relation to the show -- will we be limited to what we can do so as to not upset the current storyline, or will this serve as an alternate timeline separate from the show? One only needs to mention "Nikki and Paulo" to a Lost fan to know that adding survivors post-crash is a recipe for ire.
Producers Damon Lindelof and Carlton Cuse have reportedly worked with Ubisoft to devise the game's storyline. Said the two, "Ubisoft has done a fantastic job and come up with a game that is visually amazing and imaginative both on its own and as an extension of the world of the show." Hopefully we'll have a better idea after the trailer tonight.
[Update - The trailer has been embedded behind the break. Enjoy!]

