  We analyze the energy spectrum of reactor neutrino events recently observed
in the Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) and combine
them with solar and terrestrial neutrino data, in the context of two- and
three-family active neutrino oscillations. In the 2-neutrino case, we find that
the solution to the solar neutrino problem at large mixing angle (LMA) is
basically split into two sub-regions, that we denote as LMA-I and LMA-II. The
LMA-I solution, characterized by lower values of the squared neutrino mass gap,
is favored by the global data fit. This picture is not significantly modified
in the 3-neutrino mixing case. A brief discussion is given about the
discrimination of the LMA-I and LMA-II solutions with future KamLAND data. In
both the 2- and 3-neutrino cases, we present a detailed analysis of the
post-KamLAND bounds on the oscillation parameters.
