WASHINGTON (Reuters) - Winning The Future. Greater Together. We Don't Quit. They may not be official but those are all phrases that could in one form or another be candidates to become President Barack Obama's re-election slogan. Advisers say a fresh slogan to replace the winning "Change we can believe in" mantra of 2008, is unlikely to appear before Obama knows who his Republican opponent will be and starts big campaign travel swings, likely in the spring or summer. His campaign posters now say simply, "Obama 2012."