Theory status of (g-2)_mu and experimental prospects

he anomalous magnetic moment of the muon provides stringent tests for the electroweak Standard Model (SM) and is an excellent monitor for new physics. Being one of the most precisely measured and at the same time very precisely predictable observable in elementary particle physics, the present persisting deviation between theory and experiment is likely the best established indication of physics beyond the SM. I present a summary of the status and on recent progress of the theoretical prediction, emphasizing problems and possible solutions in the determination of the hadronic contributions: vacuum polarization and light-by-light scattering. They represent the challenge in reducing theoretical uncertainties to match the precision of forthcoming experiments, expected to go into operation within the next years at Fermilab and later at J-PARC in Japan. The impact of recent LHC results for the interpretation of the observed 3-4 sigma "discrepancy" in the muon g-2 is discussed.