At present a great amount of research work is performed to develop new magneto caloric materials, which are the refrigerants of magnetic refrigerators. This leads to a continuous development of more performant magnetic refrigerants with higher entropy differences ∆S, higher adiabatic temperature differences ∆Tad and lower hysteresis effects. Also an increased activity to design better thermo-magnetic refrigerators is occuring and numerous promising patents on machines with magneto caloric porous beds have been deposited. In a new IIR working party on magnetic refrigeration the different activity groups get into close relation, leading to welcome interactions between material scientists, physicists working on magnetism and specialists on fluid dynamics and thermodynamic machine design. All these increasing activities lead to a very high potential of magnetic refrigerators for a market penetration, which most probably at first will occur in some niche markets. After that for some main sales domains of refrigeration - e.g. as for usual commercial refrigerators - an entrance to the market also seems feasible. Other markets are in air conditioning, heat pump applications, process technics, automobile industry, medical domains, etc.