Earlier today Apple released a new developer beta of OS X 10.6.7. The build is the fourth since January, carrying number 10J855.
No known issues are reported in the seed notes, focus areas still include Mac App Store, AirPort, Bonjour, SMB and Graphics Drivers. At this point, it appears that the public release of OS X is getting closer, as Apple has been releasing new betas every week and the initial issues have been fixed and no new ones have been reported.
The third beta (10J850) was released on February 1st.
[Thanks, Bastian]