What if the tables were reversed and the G5 and Mac Pro 1,1 through 5,1 series were the trashcan design (or something similarly minimalist like the G4 Cube). Then with 6,1 Apple drops the tower form factor on us. Imagine their marketing bullet points: * Industry standard PCIe slots! * Dual CPU options! * Easy CPU upgrades! * Internal drive bays! * $500 less expensive! Oh, but it's heavier and you'll need to sacrifice more space on your floor or desk. Sorry about that!