  New results from the 2010 RHIC low energy program show a substantial
suppression of neutral pions in central Au+Au collisions at both sqrt{s_NN}=39
and 62.4 GeV c.m.s. energies. At high pT the 62.4 GeV and 200 GeV data follow
the same suppression pattern. On the other hand, otherwise successful pQCD
predictions do not describe the 39 GeV data. These observations indicate that
initial state effects may play a dominant role at smaller c.m.s. energies and
at lower pT . The azimuthal dependence of the nuclear modification factor R_AA
is strongly correlated with the (approximately elliptical) geometry of the
overlap region. The dependence of R_AA on the reaction plane, determined up to
pT=20 GeV/c from 2007 high-luminosity sqrt{s_NN}=200 GeV Au+Au data provides
great selectivity among theories, and favours the ASW scenario with AdS/CFT
correspondence over the pQCD-based models.
