We analyze both theoretically and by means of numerical simulations the
phenomena of filamentation and dynamical formation of self-guided nonlinear
waves in media featuring competing cubic and quintic nonlinearities. We provide
a theoretical description of recent experiments in terms of a linear stability
analysis supported with simulations, showing the possibility of experimental
observation of the modulational instability suppression of intense light pulses
travelling across such nonlinear media. We also show a novel mechanism of
indirect excitation of {\em light condensates} by means of coalescence
processes of nonlinear coherent structures produced by managed filamentation of
high power laser beams.Comment: 6 pages, 4 figure