The control of wall loads in fusion devices, in particular with respect to the life time limitations of wall components due to material erosion and migration, will be decisive for the realisation of a fusion power plant operating in steady state, while in a pulsed experiment like ITER the primary goal for plasma-wall interaction is the achievement of a high availability. The article describes the grand challenges of plasma-wall interaction research along the needs for ITER and the strategies of ongoing research for further optimization of the design. Addressed are questions related to material problems, erosion- and transport processes, tritium retention in deposited layers and transient heat loads.