IBM did this with the PowerPC chips used in the Playstation 3. It was a development headache but part of that was the low power cores were extremely limited... no shared memory so you had to DMA data over and double buffer. They ran mighty fast though. It was a lot like programming a DSP really. If this is anything like that I would expect only some workloads to be pushed to the small cores in a similar way to the way stuff is pushed to GPU today. Frameworks will pop up to make it easier for developers but it will be rough at the get-go.