The Exchange Calendar Update Tool for the Daylight Savings Time 2007 changes is now available for download, testing, and use in your environments. Before you run the Exchange Calendar Update tool, refer to Microsoft Knowledge Base article 930879, "How to address daylight saving time by using the Exchange Calendar Update Tool," for complete information about potential effects on your IT environment and user base.
The tool can be downloaded at the following location: http://www.microsoft.com/downloads/info.aspx?na=22&p=2&SrcDisplayLang=en&SrcCategoryId=&SrcFamilyId=&u=%2fdownloads%2fdetails.aspx%3fFamilyID%3da9336886-4b28-4010-9416-36d38429438d%26DisplayLang%3den
The Exchange Calendar Update Tool enables administrators to update, using the Time Zone Data Update Tool for Microsoft® Office Outlook®, multiple user mailboxes, thereby avoiding the challenges involved with broadly deploying the Outlook Time Zone Data Update Tool to all end-users.
Also - please continue to refer to this site for full details on the impact of Daylight Saving Time 2007 - www.microsoft.com/dst2007