The study of neutrino oscillations offers promises of great discoveries including leptonic CP violation. The experimental programs that are under discussion pose considerable challenges to accelerator builders. Extremely high intensities are needed for classical on- and off-axis pion decay beams; novel ideas such as beta-beams and muon decay beams have been invented and are being studied. The experiments to be performed require outstanding predictability and monitoring of the neutrino flux. The challenges are reviewed and a list of requirements is proposed.