Another update for worldwide time zones has been released to the Microsoft Download Center. It will soon be available as part of Microsoft Update, but for testing and pre-release evaluation purposes it is available now. From the press release:

As noted previously, the annual 2008 Cumulative Time Zone Update for Windows sets the known, correct dates for 2008 (including 2008 changes for Australia, Brazil and other countries we know that have changed their observance of DST entry/exit dates or time zones in 2008). This early drop of the update allows IT professionals and sysadmins to test the installation and deployment of the cumulative update roll-ups prior to broad distribution. The update packages will be distributed to computers via Windows Update in early December (the second Tuesday, Dec 11).

Get the update from http://support.microsoft.com/kb/942763.