Bethesda Softworks has released a detailed FAQ regarding the dedicated servers for Brink. The servers will be standalone, so they won't require a full version of the game to use them, and you can download the server from Steam before release.
The servers will come with some basic settings that span different game modes, co-op challenges, and so on. But you can also set your own custom options, including team sizes, time limits, overtime, warmup rules, friendly fire, voice chat, Command Post buffs, rank restrictions, bots, and passwords. You can run several instances of the server on one machine, if you so choose. Bethesda is allowing third-parties to set up their own custom servers for customers too.
The company also plans to pre-load the game itself on Steam, but said it will share those details in the coming days. The game is set to release on May 10, so we should be seeing that info come sooner rather than later.