In lieu of an immediate patch coming out for SharePoint. Here's one method of addressing the issue and would look like this:
Modify the TIMEZONE.XML file
1. This is in combination with the OS patch being applied first!!
2. Find C:\Program Files\Common Files\Microsoft Shared\web server extensions\60\CONFIG\TIMEZONE.XML
3. Fix the Perth entry to match the TZ patch for the O/S – should look like:
<TimeZone ID="73" Name="(GMT+08:00) Perth" Hidden="FALSE">
Obviously this will change again next year when we come into line with the East.
Again Big disclaimer: Test first! I cannot warrant any issues caused by this approach. You assume all risk!
Update: 7/12/2006 New news at hand. Some customers are reporting that this doesnt fix the DST issue in every instance. Again please test first and ensure you backup the timezone.xml file before trying this method. Will be back in touch shortly!