Could be interesting.
I'm not a fan of Steampunk, mixing technologies within a setting that apparently doesn't fit with those technologies (or vice versa) doesn't always look good... or "fits", indeed. For some reason the trailer reminded me of The League of Extraordinary Gentlemen (also to some extent, Sucker Punch, or Atlantis: The Lost Empire). The Steampunk concept can work, I do like it sometimes but on the other hand I always have that thought at the back of my mind about stuff "not fitting" and it gets annoying. I can be entertained just because it "looks cool" (like those soldiers on the spider-like mechanized legs things), or because it looks like it's still the 1940's but there's some crazy techs that seemingly come from the 22nd or 23rd century, Steampunk feels "weird" to me. The comparison to Bioshock isn't bad either, I agree they have some similitude (I liked Bioshock though).
Anyway, time will tell but I have mixed feelings about Steampunk in general, not just in video games mind you, also in movies. There's something to consider though, ultimately, it will be a console port, so I'm not expecting much for the "PC version".