The Industrial Revolution pack
If you're a fan of pre-orders, you can gain access to the "Industrial Revolution Pack" through pre-ordering at select retailers (basically everyone). You'll get access to three in-game items, 500 bonus currency, five lock picks, and the Industrial Revolution puzzle game for your troubles.
You can watch the video above for a better look, but of course, there are spoilers abound in terms of surprises, especially regarding a few enemy types.
Most of you are probably going in completely dark in regards to Bioshock Infinite. I'd probably recommend that -- so for those people, there's nothing to see here!