So I just went over to the Bethesda's Blog and read about what the XBOX patch does. Also it was reported that they know about the lag and it seems they are working towards a fix. A lot of developers say they are "looking into it" and then never do a damn thing (I'm looking at you Infinity Ward!).
It does seem that these guys [Splash Damage] are true and able. Only time will tell. This game has tons of potential for a lot of maps and weapon packs. Again, in time we shall known.
Here's the blurt from the official blog of Bethesda.
We’ve now put up our first game update on the Xbox 360, which went live at launch. It addresses several of the issues raised in some of the early US reviews of the game and brings with it some major improvements.
Most importantly, this update significantly reduced texture loading times thanks to improved hard-drive caching. It also improves client prediction when playing online – in other words, you’ll experience much less “rubber banding” in multiplayer. We’ve also fixed several issues that could lead to the game freezing, and resolved an issue where Brink would insist on playing all of the training videos rather than just the introductory one.
If you’ve not yet got the update, simply restart the game while your Xbox is connected to the internet.
We’ve also been getting new reports of lag when playing online, especially in matches with lots of human players. We’re all huge multiplayer fans here at the office and we know how important a lag-free online experience is. We’re urgently investigating this issue and seeing what we can do to improve things in that area. Stay tuned.