http://eshop.macsales.com/item/Apple/105LEOP/ Either Leopard has better specs in real life than the Developer Preview, or they are digging a hole for themselves. They say: "Apple Mac OS X 10.5 "Leopard" - Complete, New, Full Retail Box Version! *PREORDER* - Expected to ship Late October, 2007. Requires 800MHz G4 or faster, DVD drive, built in FireWire, and at least 512MB of RAM. (APL105LEOP)" As has been mentioned earlier the Developer Preview won't install on anything less than 867 Mhz. So perhaps Apple has announced to them some last second optimizations. If not, they are digging a hole for themselves by understating the specs.