  I provide a brief summary of the theory presentations at ISMD 2011 related to
the phenomenology of small-x QCD evolution and its application to particle
production and fluctuations in high-energy hadron and heavy-ion collisions. I
also mention some challenges for quantitative phenomenology which emerged from
the LHC, such as understanding the long-range "ridge" in high-multiplicity p+p
collisions, the transverse momentum distributions in p+p at semi-hard pT, and
the origin and scale of density fluctuations in the initial state of heavy-ion
collisions.
