No matter how great the game looks or how jealous gamers are of the people who got lucky due to Toys R Us messing up and selling it before the 21st, the fact of the matter is Bioshock is NOT being released early.
Brendon Lindsey, Editor In Chief of Gamernode just got off the phone with one of the PR guys over at 2K. According to him, this whole situation was just a broken street date by some Toys R Us employees who didn't know Bioshock had a street date (or didn't care), and the resulting snowball effect that caused. At this point 2K isn't entirely sure why so many Toys R Us stores went and sold the game early ("It's not like street dates are a new concept"), but they are going to look into it once they put out this fire. (Check the update below for one reason why the street date may have been broken so widely.)