Based on the analytics of readers finding last month's Spring Ahead March 11, 2007 - Computer Clock Update post, there are still a large number of computer users concerned about the time adjustments due to the changes taking effect this year.
Where Daylight Saving Time used to "spring ahead" on the first Sunday in April and "fall back" on the last Sunday in October, the timeframe has been extended so "spring ahead" will now occur on the second Sunday in March, with "fall back" on the first Sunday in November.
So, what's the big deal? Without the appropriate patches/updates, not only will your computer be out of sync with thetime change, so also will the Sun Java Engine, your e-mail calendar program as well as any mobile devices.
As I indicated in the above-linked document, if you have Windows Vista or have Automatic Updates turned on, your computer and Outlook calendar (if you use it) should be updated. See that document also for information and instructions on using the tzedit.exe utility.
For information on other vendors, Blake Handler has additional information available in Resources to Prepare for 2007 Daylight Saving Time Changes.