In a move that could very likely be a glimpse of things to come for this industry, Splash Damage and Bethesda are going to put out the first Brink downloadable content for free. This is their way of showing "appreciation for your support" of the game despite a rough launch.
A number of users have been experiencing pesky lag, so here's an update on that front. A full patch is in the works, but for now, a "configuration change" on Xbox 360 (and on PlayStation 3 once PSN is up) has been made which limits the number of human players to eight in Campaign and most Freeplay modes.
You can still get your eight vs. eight on through the Big Teams Freeplay configuration, if lag hasn't been troublesome for you. Lastly, the PC version of Brink has seen incremental updates; AI, GPU, and server issues are some of what's been targeted.
Brink: Updates Now Live & Free DLC [Bethesda Blog -- Thanks, Ali D]