Andy mentioned that there would be a administrator tool to replace the client side tool built in to Outlook 2007 and available to download for previous versions.

This adminisrative tool allows an administrator to update on each of the mailboxes appointments to work with the new DST rules once the OS and Exchange patches have been applied. 

Download the tool here.

The Exchange team put together a step-by-step guide on how to use the tool: http://msexchangeteam.com/archive/2007/02/14/435267.aspx

Read KB930879 for more info.

Note: This tool is called the "Exchange tool" or "Exchange Calendar Update Tool" in the documenation and the client tool is called the "Outlook tool".