  Recent advances in N-body simulations of cold dark matter halos point to a
substantial density enhancement near the center. This means that, e.g., the
$\gamma$ ray signals from neutralino dark matter annihilations would be
significantly enhanced compared to old estimates based on an isothermal sphere
model with large core radius. Another important development concerns new
detectors, both space- and ground-based, which will cover the window between 50
and 300 GeV where presently no cosmic $\gamma$-ray data are available. Thirdly,
new calculations of the $\gamma$-ray line signal (a sharp spike of $10^{-3}$
relative width) from neutralino annihilations have revealed a hitherto
neglected contribution which, for heavy higgsino-like neutralinos, gives an
annihilation rate an order of magnitude larger than previously predicted. We
make a detailed phenomenological study of the possible detection rates given
these three pieces of new information. We show that the proposed upgrade of the
Whipple telescope will make it sensitive to a region of parameter space, with
substantial improvements possible with the planned new generation of Air
Cherenkov Telescope Arrays. We also comment on the potential of the GLAST
satellite detector. An evaluation of the continuum $\gamma$-rays produced in
neutralino annihilations into the main modes is also done. It is shown that a
combination of high-rate models and very peaked halo models are already
severely constrained by existing data.
