Apple has seeded a new version of Mac OS X 10.6.3 to developers today. The last seed was released on January 22nd. According to reports, the newest version provides a number of enhancements and bug fixes for QuickTime X, 64-bit Logic, printing and OpenGL.
There are said to be "no known issues" with the latest build, possibly indicating that we may be approaching release. 10.6.3 only began seeding to developers in early January but 10.6.2 saw a comparably short time frame from initial seeding to public release.
The Mac OS X 10.6.2 update was released on November 9th.
Article Link: Apple Seeds Mac OS X 10.6.3 (Build 10D548)