  Motivated by some new experimental and theoretical efforts, we update the
theoretical analysis of the electron-positron energy asymmetry, which arises,
in K_L --> pi0 e+ e-, from the two-photon intermediate state in the standard
model. It is found that the measurement of this asymmetry in future experiments
may increase our understanding of the K_{L, S} --> pi0 e+ e- decays, which
would thus provide some useful information on quark flavor physics. Meanwhile,
in the standard model the electron-positron energy asymmetry in the decay of
K_S --> pi0 e+ e- is expected to be vanishingly small, therefore the asymmetry
in K_S --> pi0 e+ e- might be a very interesting quantity to explore new
physics scenarios.
