  We present a general scenario for high-temperature superconducting cuprates,
based on the presence of dynamical charge density waves (CDWs) and to the
occurrence of a CDW quantum critical point, which occurs, e.g., at doping
p~0.16 in YBCO. In this framework, even the pseudogap temperature T* is
interpreted in terms of a reduction of the density of states due to incipient
CDW and, at lower temperature to the possible formation of incoherent
superconducting pairs. The dynamically fluctuating character of CDW accounts
for the different temperatures at which the pseudogap (T*), the CDW onset
revealed by X-ray scattering (T_{ons}(p)), and the static three-dimensional CDW
ordering appear. We also investigate the anisotropic character of the
CDW-mediated scattering. We find that this is strongly anisotropic only close
to the CDW quantum critical point (QCP) at low temperature and very low energy.
It rapidly becomes nearly isotropic and marginal-Fermi-liquid-like away from
the CDW QCP and at finite (even rather small) energies. This may reconcile the
interpretation of Hall measurements in terms of anisotropic CDW scattering with
recent photoemission experiments.
