NVIDIA white paper on variable SMP

Have you read about NVIDIA's Project Kal-El processor? It implements a novel variable Symmetric Multiprocessing technology.

Essentially, there are five processors in this architecture. Four are designed to work at higher frequencies and the fifth at a much lower frequency. The low frequency chip will work on rendering multimedia. Based on the workload, these chips are enabled and disabled. The fifth CPU is called a companion which is not OS sensitive.

My question would be who would decide the enabling and disabling strategy? And at what level? If multiple programs act on enable/disable settings, would there be a middleware that takes sensible, real time decision?

What's it all about? Would it save energy without compromising on performance?
Read the whitepaper below for more information
SMP: A Multicore CPU Architecture for Low Power and High Performance