  Recent work on the connection between in-medium subthreshold $K^-N$
amplitudes and kaonic atom potentials is updated by using a next to leading
order chirally motivated coupled channel separable interaction model that
reproduces $\bar KN$ observables at low energies, including the very recent
SIDDHARTA results for the atomic $K^-$-hydrogen $1s$ level shift and width. The
corresponding $K^-$-nucleus potential is evaluated self-consistently within a
single-nucleon approach and is critically reviewed with respect to empirical
features of phenomenological optical potentials. The need to supplement the
single-nucleon based approach with multi-nucleon interactions is demonstrated
by showing that additional empirical absorptive and dispersive terms, beyond
the reach of chirally motivated $K^-$-nucleus potentials, are required in order
to achieve good agreement with the bulk of the data on kaonic atoms.
