A significant change of philosophy from traditional solid state and manybody approaches appears necessary to describe many classes of complex electronic and structural materials, both inorganic and organic. This is evident from more than a decade of rapidly improving experimental data resolution, and increasing failures of traditional interpretative frameworks. We conclude that multiscale complexity is fundamental to the science of synthesis-structure-property relationships in many "complex" materials. Measuring, modeling and using this complexity will be the basis for new generations of technology. A large class of such multiscale complexity appears to be driven by competitions of short- and long-range forces, resulting in "landscapes" of spatio-temporal patterns and metastable states, and associated glassy, hysteretic dynamics. We briefly summarize various materials and condensed matter systems exhibiting these competitions, including examples from: Josephson junction arrays and flux flow; surface morphology and evolution; organic self-assembly; polyelectrolytes and biomolecules; and complex organic and inorganic electronic materials. We emphasize challenges for theory and modeling; namely accurate incorporation of nonlinear, nonadiabatic, and nonequilibrium ingredients which are inescapable for the multiple, connected functional scales which constitute complex "systems".