  Clear methods to differentiate between decaying and annihilating dark matter
(DM) scenarios are still by and large unavailable. In this note, we study the
potential astrophysical signatures of a new class of hidden sector decaying DM
models, which can address the recent cosmic ray measurements. Such models may
produce primary photons and/or neutrinos at large rates, correlated with the
leptonic production. The photon and neutrino spectra will then contain sharp
features at the TeV scale. We demonstrate the discovery potential for upcoming
and future measurements by FERMI, HESS, AGIS and IceCube/DeepCore. We show that
these models may be discovered in the near future. Specifically, measurements
of diffuse gamma rays by FERMI can detect the start of a hard photon feature.
We argue that these hard spectra can be produced by decaying dark matter and be
consistent with current constraints, but are difficult to reconcile with models
of annihilating DM. Consequently the measurement of a hard spectral feature, in
correlation with the current cosmic ray measurements, will strongly favor
decaying DM models. Finally we comment on the preliminary results from the
Inner Galaxy presented by the FERMI collaboration.
