It probably will not run at an acceptable frame rate. Even on an x86 with the dynamic recompiler, 700MHz is probably not fast enough to achieve real-time playback. Without the dynarec (PPC can only run the interpreters) it won't even come close. I did once run across a "Google summer of code" page for a project that was aiming to port Mupen64's dynarec to the PPC architecture. I don't know how far they got with that.