Not open source, I think
> The PowerVR MBX supports the open source OpenGL ES 1.1 API set
I don't think that's entirely true. OpenGL is an open specification, i.e. anyone can write a program that uses it; however, the hardware-level programming information for how to map from OpenGL to the PowerVR chip's registers is secret. So, for example, you can write a program for the iPhone that uses it because Apple know the secrets, but if you have something that runs Linux like the Beagle Board or the Open Pandora you have to jump through hoops like this:
I doubt that Apple's investment is going to make this any better.