Lisa Randall in Prospect Magazine:
In a couple of years, we might be forced to radically revise our ideas about the underlying nature of matter and our conception of the universe. In 2007, the large hadron collider (LHC) will begin operating at Cern, near Geneva, boosting particles to energy levels that have never before been produced on Earth. Physicists will then combine results from the LHC experiments with insights from their theoretical investigations to explore phenomena whose effects are only detectable at small distances and high energies.
The theory known as the Standard Model of particle physics describes all known matter and the forces through which it interacts. Experiments have thoroughly tested the Standard Model, and its basic ingredients are almost certainly correct. But the Standard Model cannot be the final word: it leaves open important questions about the origin of elementary particle masses and puzzles such as the relative weakness of gravity. The LHC will help to resolve these mysteries, and scientists all over the globe are busily preparing experiments they hope will provide answers to these questions.
More here.