The polyelectrolyte extraordinary diffusion regime encountered in low-salt polyelectrolyte solutions is proposed to be a material example of the cluster-forming glasses simulated by Johnson et al. Features common to both types of system include (i) cluster formation, (ii) slow/glassy dynamics in which clusters participate while individual molecules move relatively freely, and (iii) a peak in the static structure factor at nonzero scattering vector that scales with the interaction strength. The neutral polymer slow mode also seen with light scattering spectroscopy has quite different properties and corresponds to a different class of glassy dynamics.