Apple today seeded Mac developers with a new version of Mac OS X 10.6.8, termed Build 10K537.



From MacRumors:

The new build, which continues to weigh in at about 1 GB as a combo update and is approaching 500 MB as a delta update, is the first to be pushed out to developers in over three weeks as Apple's team has undoubtedly been focused on WWDC.

  Mac OS X 10.6.8 Build 10K537 Seeded to Developers