My friend Joshua Elder pointed this out first, I think, but Doug Wolk explains it all . That new issue of Action Comics wherein Superman renounces his American citizenship? Actually not a big deal.
Superman, it turns out, has recently visited Tehran, where he joined a demonstration and stood, silently, for a day, in solidarity with the protestors. The government of Iran has decided that Superman's acting on behalf of the U.S., and that his presence was an act of war; Superman responds by saying "I intend to speak before the United Nations tomorrow and inform them that I am renouncing my U.S. citizenship. I'm tired of having my actions construed as instruments of U.S. policy... I've been thinking too small. I realize that now."