Bio Shock Infinite Prequel Or Something Totally New?!

Late Wednesday night we were treated to a first look at "Bio Shock Infinite" and I must say it looks crazy! A flying city called "Columbia" what you first think is a return to "Rapture" is actually the lead protagonist being drowned in his own fish bowl then thrown out a window of a high rise plunging to his death falling through a city floating on the clouds?! This left more questions than answers, is this a prequel, seeing its set in 1912 with all the turn of the century steam punk influenced atmosphere or is this a completely different story? This is being produced by the team that did "Bio Shock" Irrational Games but from what is being said we have until 2012 to try and figure out that puzzle, heres a first look.