State management is a basic requirement for multiuser virtual environments (VEs) such as Massively Multiplayer Online Games (MMOGs). Current MMOGs rely on centralized server-clusters that possess inherent scalability bottlenecks and are expensive to adopt and deploy. In this paper, we propose Voronoi State Management (VSM) to maintain object states for peer-to-peer-based virtual worlds. By dynamically partitioning the VE with Voronoi diagrams and aggregating game states of overloaded nodes onto superpeers, VSM supports existing consistency control to enable scalable, load balanced, and fault tolerant VE state management. As both client and server-side resources are utilized collaboratively, VSM also integrates both client-server and peer-to-peer VE designs in a unified approach.