While the game is supposed to be action packed and visually stunning without the day one patch, the Xbox 360 version might not have been equal with the other platforms.
The patch will address irregular visual glitches at distance including texture pop-up and solve a few small networking issues that have been discovered. Fortunately these problems have been found thus the day one patch will be automatically downloaded and installed.
Brink will be released on the 10th of May.