  Theoretical talks and discussions at Rencontres de Moriond 2004 "QCD and
Hadronic Interactions" are summarized. Following exciting recent experimental
discoveries, theoretical developments were reported in the description of heavy
ion collisions, light hadron spectroscopy, and the physics of hadrons
containing heavy quarks. Some of the predictions have already been tested by
subsequent experiments, notably by the very recent SELEX observation of a
possible new charm-strange meson D_{sJ}(2632).
