AppleInsider reports that new seeds of Mac OS X 10.6 Snow Leopard were recently distributed to developers.
The newest seed of Mac OS X 10.6 is said to offer new additions to Grand Central, which provides developers an easier way to harness the power of multiple processor cores. Apple's efforts to convert many of its existing apps to Cocoa are still underway but with much still left to be done on Font Book. Other areas that are undergoing ongoing revisions include power management for notebooks and 64-bit support.
While there had been some hints that Mac OS X 10.6 might arrive in the first quarter of 2009, Apple's official timeframe was "about a year" from this past June.
Update: Seed notes posted.