  Very high energy resolution photoemission experiments on high quality samples
of optimally doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ show new features in the
low-energy electronic excitations. A marked change in the binding energy and
temperature dependence of the near-nodal scattering rates is observed near the
superconducting transition temperature, $T_C$. The temperature slope of the
scattering rate measured at low energy shows a discontinuity at ~$T_C$. In the
superconducting state, coherent excitations are found with the scattering rates
showing a cubic dependence on frequency and temperature. The superconducting
gap has a d-wave magnitude with negligible contribution from higher harmonics.
Further, the bi-layer splitting has been found to be finite at the nodal point.
