Note #1: This post links to discussion boards that use colourful language. If you don't like that sort of thing, don't click any non-numerical links below.
Note #2: If Elected, I Solemnly Promise: As a suggestion to governments for next time around: If the objective was to get the Closing Ceremony televised at the same time as the Opening Ceremony, perhaps just moving the end of Daylight Savings Time by just a day from the Sunday to Monday morning might have been enough to achieve the objective?
Anyway - thought I'd mention that 912475 - the Australian Windows DST patch for non-Exchange environments - was installed on all my PCs (5 physical - XP x64, WS2003, XP 32-bit x2, MCE, and a virtual WS2003), but the Media Centre ticked back over to Standard Time a week early anyway.
There have been some reports of others finding the same thing - doing a quick trawl of the net, it looks like this problem is cropping up a bit, but doesn't seem to affect the majority of computers.
It looks like the probable cause is that the time zone information stored under HKLM\System\CurrentControlSet\Control\TimeZoneInformation might not have refreshed for some reason when the patch was installed.
Going into the Time Zones tab of the Date and Time Control Panel and re-selecting the current Time Zone is enough to refresh that registry key and right the clock (ie, I skipped a step from those listed by someone else reporting the problem here - it might even be enough simply to hit the Time Zones tab and OK), and it seems to work consistently, so if you've installed the update and have a recalcitrant clock, try that first. If you're set to synchronize with an external time source other than the default time.windows.com, try changing that next.
I'll be looking into this situation some more tomorrow; in the meantime, re-selection seems to work for everyone that's installed the patch.
The other DST Update (909915) always required the user to pick a "Comm Games" time zone manually (though scripty options were provided).