Performance gains outside of FPS wankfests would be marginal, maybe even negative when comparing the 2x2.7Ghz to the 2.5 Quad and AGP G5 aren't that hard to come by.

If MorphOS goes SMP on PPC before going x64 those G5s and the X5000 (and even some G4) would be more then enough for testing. Once that move has been made (and binary compatibility gone for good) there is no point in sticking with the sinking ship that is PPC.

-> waste of resources for little to no gain