Apple seeds Mac OS X 10.4.6 8I1113 (intel) and 8I120 (PowerPC)
The builds don't have any known issues currently and are expected to be released tonight or tomorrow - unless a bug is submitted that has to be fixed. Changes in the current seed contain a fix to Help Viewer, some fixes to Core Graphics and CoreImage, an issue with WebKit (and plugins) and an iSync/iPod Conduit fix.
Generally, Apple says the following things are seeing improvements from 10.4.5 to 10.4.6: Sharing using AFP, SMB/CIFS, NFS and FTP file sharing protocols; Reliable access to Open Directory, LDAP and Active Directory services; Login and authentication in a variety of network environments, File access and byte range locking with AFP file sharing; Network access when using proxy server automatic configuration files; Connecting to Cisco VPN servers using IP/Sec and NAT; AirPort and Bluetooth wireless connectivity; RAW camera support, including updated ATI and NVIDIA graphics drivers; Usability of Dashboard and widgets; Searching iWork '06 and Microsoft Office documents with Spotlight; Saving Word documents automatically when using a network home directory; Viewing of QuickTime streaming media behind a firewall; Creating Automator workflows for iPhoto 6; Synchronizing contacts and calendars to .Mac and mobile phones; Mounting and unmounting iDisk volumes; Time zone and daylight savings for 2006 and 2007; Address Book, AppleScript, Automator, Dictionary, Font Book, iCal, iChat, DVD Player, Mail, Preview, Safari, and Stickies; Disk Utility, Keychain Access, Migration Assistant, and Software Update; Compatibility with third party applications and devices.Update:
Apparently, this build disables the backlight-feature of some PowerBook keyboards in some way, so at least one newer build is expected before the update can be released through Software Update and the preferred combo updaters on Apple's support pages...