ET:QW had ways to punch through turtle defenses: you could order fire support, and as long as they didn't have an artillery interceptor, you could absolutely ruin their deployables as well as deny them a certain part of the map for a little while. (If they did have an artillery interceptor, you could still order air strikes using a colored smoke marker, or just get an Operative to hack the interceptor before you start shelling.) The equivalent in Brink will probably be those "area denial grenades" Soldier is supposed to get. Tear gas will likely snake around corners and into windows where normal grenades would have a tough time reaching. Operatives can also use smoke grenades to block the enemy's sight so their team can advance.
Overall, I don't worry about SD failing to address camping. They want to make a game they can play and have fun, and if the defending team can bunker down and not do anything interesting, and win, then they will get irritated and change it.
