In this chapter we address how the landscape of mobile HCI is changing. With a point of departure taken in how mobile interaction design is nowadays not only about interface design for digital devices, but about the design of wide-ranging interaction landscapes we explore how mobile HCI are now heavily interwoven in complex arrangements of computational devices, platforms and services. In exploring these current developments, this chapter identifies three contemporary strands of developments related to 1) the formation of new interaction landscapes, 2) the long tail of interaction, and 3) digital materialities. With a point of departure taken in these three strands, this chapter presents a research agenda for moving forward followed by a discussion on the implications of this agenda for mobile HCI research.