Mostly a TDM will make me dig a hole light the inside of the hole on fire then drop the game into the pit of fire
Except of course Splash Damage would never subject us to that kind of sheer idiocy.
I honestly can't think of what could ruin Brink for me. I mean, they've taken so much time and effort to remove everything that makes gaming (especially multiplayer) [censored] and leaving all the nice bloody juicy tender bits for us to tear into tooth and nail. I look at this game and see a restructuring of the gameplay sandbox the way Halo: Reach reshaping their sandbox with the new shield physics, weapons, and Armor Abilities. But Brink takes it to a much higher level. Splash Damage has worked insanely hard for this; I think they have the experience and the drive to deliver all the wonders and treasures they've promised with this game.
So no, there is nothing within reason that makes me think there can be anything to ruin Brink.