The game comes out October 16th in North America across all platforms. It's safe to assume it'll be two days later for the UK and Yurop.
“After BioShock, we had a vision for a follow up that dwarfed the original in scope and ambition,” said Ken Levine creative director of Irrational Games. “BioShock Infinite has been our sole focus for the last four years, and we can’t wait for fans to get their hands on it.”
I'm getting it, looks awesome.