Simulations of laser-plasma interactions show saturation of Raman scattering through novel subsequent Brillouin and Raman rescattering instabilities. This behavior alters the interpretation of experimental diagnostics as well as the distribution of laser energy between transmission into the target, scattering losses, and generation of energetic electrons. This paper emphasizes targets that are predicted to reach electron temperatures greater than 10 keV, a value accessible today on the Omega and Helen lasers and one which will be far higher at future facilities. In such plasmas, the nonlinear laser-plasma interaction exhibits novel features presented here.