In this review we present an overview of the literature on the co-assembly of neutral-ionic block, graft, and random copolymers with oppositely charged species in aqueous solution. Oppositely charged species include synthetic (co)polymers of various architectures, biopolymers - such as proteins, enzymes and DNA multivalent ions, metallic nanoparticles, low molecular weight surfactants, polyelectrolyte block copolymer micelles. metallo-supra molecular polymers, equilibrium polymers, etcetera. The resultant structures are termed complex coacervate core/polyion complex/block ionomer complex/interpolyelectrolyte complex micelles (or vesicles); i.e., in short C3Ms (or C3Vs) and PIC, BIC or IPEC micelles (and vesicles). Formation, structure, dynamics, properties, and function will be discussed. We focus on experimental work: theory and modelling will not be discussed. Recent developments in applications and micelles with heterogeneous coronas are emphasized. (C) 2008 Elsevier B.V. All rights reserved.