Bioshock Infinity and Beyond

Bioshock Infinite is set in a Steam-Punk cloud city, floating over the American states, which is a far cry from the Underwater biodomes of Bioshock 1 & 2.

I was wondering what the connection was to previous game, besides Plasmid-like powers and the Political power struggles and after watching the 15-minute game play trailer, I literally went "OOOOH" when the Song Bird showed up.