Stellar atmospheres represent unique windows for understanding
stellar, galactic and cosmic evolution by being responsible for
the emission of stellar spectra. Much progress has been made over
the years in modelling stellar atmospheres but still the modelling
efforts are hampered by various, often questionable, assumptions
and approximations. This review describes promising avenues for
improving the realism of stellar model atmospheres for hot
(spectral types O, B, A), cool (F, G, K)
and very cool (M and later) stars, respectively, in the coming decade.
A common theme will be time-dependent 3D hydrodynamical calculations
with a detailed non-LTE treatment of the radiative transfer.
It is argued that this is fully within the realm of possibility
on this time-scale and indeed will be necessary to complement
the expected advances on the observational side.