Those familiar with the build, titled 10C540 have said that it contains fixes for AirPort performance issues on the newly released iMacs and also resolves a problem which arose when plugging and unplugging a system to an Apple TV. A VMWare fix is also included, presumably for the newly released Fusion version 3.0.
The new build also fixes reported panic issues with USB, Apple Filing Protocol, and some video cards.
In the 10.6.2 update, Apple plans on fixing and tweaking nearly 150 OS X components.
Some components slated for fixes include: AppleBacklight, Battery Menu, Dictionary, Expose, FileSync, Family Controls, Fonts, Front Row, HFS, Inkwell, iPhoto, MobileMe, OpenCL, Parental Controls, QuickTime, Screen Sharing, Spell Checker, Spotlight, Time Machine, and USB.
Mac OS X 10.6.2 is expected to be released sometime in November and will reportedly be around 480 MB in size.