Developments over the past several years have led to renewed study of theoretical methods for treating scattering of ultrasound by defects in elastic solids. Characteristically, many theories of scattering, until a few years ago, dealt with scalar waves and simple obstacles. Within that context two distinct regimes were apparent -- the long wave length, and the short wave or imaging regime. The treatment of vector fields in elastic solids is considered the more cumbersome, but we now have made progress -- still for idealized configurations. Specifically, the talk will deal with hypotheses on the types of problems which face us in the next generation of situations.