My take on it is that it is closer to a Diesel-Electric setup than a hybrid. The breakthrough here being the weight reduction of the electric motor itself. Diesel-Electric has it advantages in high-power installations more commonly found on ships or trains, the downside being the weight of the whole installation, you have to add a generator and an electric motor instead of a gearbox. In big land/sea based power installation having the combustion engine run at a constant speed at its optimum design rpm saves a lot of fuel and will outweigh the weight savings of a gearbox. If Siemens managed to reduce the weight of the generator and electric motor to a point where it becomes a viable installation on aircraft the potential benefits are plentyful. A more redundent power installation, if one generator would fail, all propellors could be powered from the remaining generator(s). Plus the aerodynamic advantages of a much a more flexible system layout.