This paper summarizes some of the outcomes of an investigation activity aimed at analysing the benefits of different system architectures and technologies for next generation S-band mobile satellite interactive / broadcasting networks. Along with advanced antenna and payload architectures, a promising way forward in this context is the migration from the conventional single polarization per beam to an advanced dual polarization per beam architecture for effective spectrum exploitation. In this framework, system capacity results are presented and they highlight potential improvements in a 60% to 90% range in terms of system throughput.