MotionBuilder 2009 has a wider variety of motion editing tools to create and blend animation from multiple sources.
Maya Assets enable complex data to be effectively organized, shared, referenced, and presented to a variety of users in the most appropriate form.
Maya nParticles is the second module built on the Maya Nucleus unified simulation framework. nParticles can be used to simulate a wide range of effects including liquids, clouds, smoke, spray, dust.
Polygon modelers and texture artists can be much more efficient, thanks to a wide range of new features and workflow enhancements in Maya 2009.