Apple this evening released Mac OS X 10.4.1 Update, which delivers overall improved reliability for Mac OS X v10.4 and is recommended for all users.
The release includes improvements to:
file sharing using AFP and SMB/CIFS network file services
using DHCP in wireless networks
user login when accessing LDAP and Active Directory servers
core graphics including updated ATI and NVIDIA graphics drivers
synchronization with .Mac
Address Book, iCal, Font Book, Mail, and Preview applications
Dashboard widgets: Address Book, Flight Tracker, Phone Book, and World Clock
creating and burning disk images using Disk Utility and System Image Utility (Remove)
compatibility with third party applications and devices
More detailed information and a specific list of fixes included in the release can be found in an Apple Knowledge Base article.
As of press time, Apple had yet to make Mac OS X 10.4.1 available via Tiger's Software Update Mechanism. The 37MB release is currently available from this page.