Executive summary: CMS has discovered a new particle fully compatible with the Standard Model Higgs boson (so far: all channels are within 1 sigma from the Standard Model) at 5.0 sigma at diphoton and ZZ channels; when all the other channels are included, the significance drops to 4.9 sigma. Their Higgs mass is 125.3 ± 0.6 GeV.
ATLAS has made a 5-sigma discovery, too. The same channels, the mass is around 126.5 GeV. All ATLAS' channels exactly agree, within 0.5 sigma, with SM+Higgs predictions except for diphoton channel that is almost 100% above predictions. Gianotti hasn't been scared by Comic-Sans haters and used the same font again. Papers with details by the end of July.
Congratulations to everyone involved! Lisa Randall just wrote me that I was right about the coming discovery, so small congratulations to me, too. ;-)
At 9:00 Central European Summer Time (midnight California Daylight Saving Time), a 2-hour-long seminar followed by a press conference starts at webcast.CERN.ch. You should open the video in another window and participate in the chat below, too. You will be able to ask and answer questions over there.
The discovery of the Standard-Model-like Higgs boson is one of the deepest confirmations of a theoretical prediction in the history of science. While the theory isn't too difficult, it's very far from being trivial, too. Imagine you were only given the list of particles found before the Higgs boson, their spins, and their masses.
Without a lot of theoretical work, you couldn't say anything about new particles.
Nevertheless, it is possible to predict the existence of new particles. And in the case of the Higgs boson, it is a completely new kind of a particle because it is the first spinless elementary particle we have discovered in Nature. Its difference from the other elementary particles we know is more qualitative than the differences between any pairs of others.