He still may - or may not - renounce his American citizenship. But Superman apparently still loves the USA, as in the latest strip "Superman #711."
Bleeding Cool website reports:
And to quote; "That's what America is about, really. That's the American way. Life, liberty and the pursuit of happiness - and second chances. None of us are forced to be anything we don't want to be. When I was young I knew that I would be someone different when I grew up. I would leave home and make a new life for myself. A new start, a second chance. When I first went to Metropolis, it was full of people who'd done the same thing. People from all over America - from over the world - who went to the city to live the lives they wanted - to be the people they wanted to be. That's the idea that America was founded on, but it's not just for the people born here, it's for everyone. And it's for people like me and Livewire too." - Superman.
As to whether or not he still has US citizenship, that's a story for another day.
Indeed, the reaction to the leaked news that Superman would go to the UN and renounce his American citizenship was so overwhelming that it is an open question whether DC Comics will go with the strip in question. Overseas, it seems that the rest of the world doesn't mind while in America, the outcry against the move is loud and emotional.