After seeding Leopard 9A528d just yesterday, Apple has released 9A559 to ADC members tonight. Yesterday's update appears to have been primarily testing Leopard's Software Update mechanism.
The 6.55GB download lists only two known issues for Leopard. The two issues described involve upgrading from Tiger to Leopard on PowerPC systems in certain scenarios, and HP printer drivers.
As mentioned yesterday, Apple will need to finalize Leopard soon in order to meet their October shipping deadline. Apple had originally slated Leopard for earlier this year, but announced in April that it would be delayed until October.
Apple has detailed many of the features of Leopard on their website.
