Muon Collider: Plans, Progress and Challenges
  We in the physics community expect the LHC to uncover new physics in the next few years. The character and energy scale of the new physics remain unclear, but it is likely that data from the LHC will need to be complemented by information from a lepton collider which can provide for precise examination of new phenomena. We describe the concept, accelerator design, and detector R&D for a high energy Muon Collider as well as the challenges associated with the machine and its detector environment. 
Ronald Lipton
physics.acc-ph hep-ex