I'll cast another vote for deciding based on traffic, not the rider's being left or right handed. Riding in the US, I'm more concerned with signaling left turns and being able to brake, so my preference is to have the right hand control the front brake (stronger braking) while being able to signal with the left hand. I've switched most of the bicycles that I ride frequently.

Obviously, this preference can and should be over ruled in the case of the riders preferences or injuries. I'll also admit that I'm glad the rod brakes on the Raleigh DL1 are set up for the front brake with the right hand. I have no desire to try to switch the brake attachments for the rods, so I'm glad they are set up well for US braking.