Thursday July 9th, 2009 afternoon; Apple seeds Mac OS X Leopard Developer Preview Build 10A402. The update is available through Software Update and weighs in on 1.31GB.
As usual, Apple Developer Connection members are bound by the Non-Disclosure Agreement (NDA).
From Software Update:
This Snow Leopard Developer Preview Update is recommended for all users running the Snow Leopard Developer Preview Build 10A394 or later. This update includes general operating system fixes for stability, compatibility, and security.
Mac OS X 10.6 Snow Leopard Developer Preview is not recommended for casual users and production system since it still contains numbers of software bugs.