I think everyone's made really interesting points, but so often the Bible has been used to empower oppressors and keep the weak in their place "Slaves obey your masters etc."
I think the cultural context applied to this text brings it into a totally new light. Is this not exactly what civil rights activists did? The interesting thing about passive resistance is that not only does it avoid violence and give control to the oppressed it also forces the oppressor to think. "Why won't you fight back?", "Why are you being so kind to me?" etc.
People are so willing to see Jesus as just the submissive Lamb of God when there are many facets to who He is. They forget the place He grew up in, the people He grew up with, can you imagine what Simon the zealot would have thought of this? Jesus telling him there are more ways to fight back than your sword and your fists? I think that is part of the Kingdom on earth. Fighting injustice without causing harm.