  After the PAMELA finding of an increasing positron fraction above 10 GeV, the
experimental evidence for the presence of a new electron and positron spectral
component in the cosmic ray zoo has been recently confirmed by Fermi-LAT. We
show that a simple phenomenological model which assumes the presence of a
primary electron and positron extra component allows a consistent description
of all available data sets. We then describe the most relevant astrophysical
uncertainties which still prevent to determine the electron+positron source
properties from those data and the perspectives of forthcoming experiments.
