Just for information: the PowerPC is not at all dead, it's not even close to dead, it's still being actively pushed forward by some big companies, and is evolving all the time.
Just because PowerPC isn't used in desktops any more (apart from ours) doesn't mean it's dead - nor does that fact that it's slower than x86 mean it's dead. PowerPC isn't competing with x86 any more, it's competing with ARM. That's why our Sams and things are so power efficient, they're embedded CPUs, not designed to compete with x86 desktops (what would be the point? It'd be corporate suicide).