Not a CVT
I've got to say this: the planetary gear in the Toyota hybrid design is not a CVT. It is not variable in any way.
CVT normally refers to belt transmissions with variable pulleys. Toyota use these increasingly, using the AISIN design which is computer controlled (and very effective - it is almost as smooth as a hybrid.)
The Toyota hybrid is quite different. The planetary gear on the Prius couples a petrol engine, a motor generator and an electric motor. To get variable effective gear ratio, the petrol engine can drive the wheels directly, or provide power to the motor generator which spins in reverse, and which then supplies power to the main motor. Effectively the engine revs are split between the road and the generator, with the generator providing additional torque via the main motor. The battery is there to allow extra power to the main motor for acceleration, to provide initial starting power, and to extract energy from the system for braking or regeneration.
It is an extremely clever system but too complex for the average person to understand, so I can understand the careless shorthand of calling it a CVT. The principle, however, is as different from a normal CVT as a normal CVT is from a slushbox.