Okay....take my c&c as a grain of salt, but I'll get the ball rolling for your thread.
First....were they really mad? They don't look very happy which may have been the look you were going for since brothers usually tend to fight a bit.
Second.....I can't say that I care for the post processing (some surely will though, just not my taste). Both faces seem washed out and lost detail especially the boy on the right (camera right). The entire picture seems a bit soft as well, but I think that's due to the PP and probably the look you were going for.
Edit: By the way. Some very nice photos on your website. It inspires me to try and start setting up shots with my son instead of merely "grabbing the action".