Apple has reportedly handed developers a new Snow Leopard seed this week. Labeled 10A402, the fresh 10.6 build weighs in at over a gigabyte and, just like the seed before it, comes via the operating system’s built-in Software Update mechanism.

A post over at World of Apple stands to confirm that, “Apple has today issued a new update to Mac OS X Snow Leopard via the built-in Software Update application. The update which pushes Snow Leopard to build 10A402 weighs in at 1.31GB.” Early tests have shown visible changes, such as tweaked Dock menus, according to the same source, which now appear “in a black HUD style,” as well as altered check boxes within applications, and magnifier knobs.

Apple doesn’t greet developers with too many details through the Software Update application, saying only that, “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.”

World of Apple, which is almost always the first to provide the complete seed notes for every new developer build, whether it’s incremental updates to the existing OS, or new betas of Snow Leopard, promises to post screenshots of the new developer release soon. The seed notes for Mac OS X 10.6 Build 10A402 should also be made available momentarily.

Last time we reported that Apple had seeded developers with a new build of Snow Leopard, the company had enabled the Dock Expose feature showcased at this year’s WWDC conference. During the keynote address, Apple’s Senior Vice President of Software Engineering revealed that Snow Leopard users would be able to click and hold an application icon in the Dock, and all open windows in the application they selected would "unshuffle" so they could quickly change to another window. This and many other enhancements make Snow Leopard a highly anticipated upgrade of the Mac OS.