The approach of Blackwell et al. is used to model the rheology of concentrated hyperbranched polymeric systems. Model predictions for a poly(ether imide) hyperbranched system are in good quantitative agreement with the experimentally observed behavior of AB/AB(2) copolymers. The poly(ether imide)s are especially suitable for studies of entangled dynamics because of their low entanglement molecular weight. A 3-4 orders of magnitude rise in the zero shear viscosity is observed as the mole fraction of linear segments is varied from 0 to 1. The average mass of segments between branch pints is the most significant architectural parameter that affects the rheology of these systems.