Higgs. Exciting, but now I want to know what kind of Higgs they have found, and that will take years more.
They have some brilliant communicators at CERN. Incandela at CMS is great, even when tired, (CERN 'Higgs Boson' Announcement: We Have Observed A New Particle) and the Press Office rocks. I love the "what comes next" end to their press release.
"So once the discovery is confirmed, the next question is: 'What kind of Higgs boson do we have'? Positive identification of the new particle's characteristics will take considerable time and data. It's rather like spotting a familiar face from afar; closer observation might be needed to tell whether it's an old friend who loves coffee, or her identical twin sister who favours tea. But whatever form the Higgs particle takes, our understanding of the universe is about to change."
CERN Press Releases