Both ATLAS and CMS have legitimate, crazily cross-checked data and therefore they are releasing it. That's all. This is how science is done - all CERN is doing is updating the world on its of progress the search for the Higgs boson. Sure, sometimes mistakes are made. But you'd have to be an idiot to think that scientists pull these for publicity. Press is a pain in the ass and we try to stay away from them as much as possible.