PSP2 to be based on iPhone-esque PowerVR GPU, rival original Xbox in power?

If Sony's PSPgo was some halfhearted attempt to quell incessant PSP2 rumoring (and our favorite PSP2 mockup render, above), it certainly doesn't seem to have worked. The new rumor out and about is that the inevitable PSP2 will harbor a PowerVR GPU along the lines of what's present in the new iPhone 3GS. The SGX543MP cited has four cores, with a rating of 133 million polygons per second at the low-end 200MHz mode that seems likely for portable use. calls this a "ballpark match" for the original Xbox, with some additional Dreamcast rendering enhancements for avoiding wasting time on hidden elements in a scene. They also point out that Imagination Technologies calls the chip a GP-GPU, capable of handling computing tasks in addition to graphics, and potentially giving the PSP2 the power savings of not needing a separate CPU to operate. Sure, it's all a difficult to pin down rumor at the moment, but if anything these sort of specs show what's possible for a new generation of handheld gaming when the likes of Sony and Nintendo are ready to give it to us. Now about a second analog stick...