Holy shit, this I was not expecting from Irrational. Mind officially blown.
Are you psyched for this game? I was a huge fan of the original, and it was nice to return to Rapture in the sequel, but seeing the franchise return to Levine's hands really makes me happy.
However, the time-frame (early 1900's) could present a few problems. I don't see how the music will be as interesting (I'm not really keen on any of the music from the 1910's, in fact), and I don't know if portable machine guns had even been invented that early on. However, I do know that nothing even close to sound recording devices had been made, so I don't know what they'll do with the cassette portions.
Also, since it's set in the sky, how will the powers play out without the sea slugs/little sisters required for plasmids? The setting seems surprisingly cheery in contrast with the constant feeling of impending doom that was Rapture.
Still, there's really no question that I'll be picking this up day one.