Here you find some information as well as some web resources to get pointed in the right direction concerning the DST changes in 2007.

A good place for anyone to start is some of the links below

 

Also the version 2 of the Exchange Calendar Update Tool went live last night on Feb 21st.  KB  |  Download

Key improvements over V1:  ~2x performance improvement when MSEXTMZ.exe is running in Update Mode, improved user interface, fixed memory leak that caused the need to frequently restart the client machine, improved algorithm for mapping extracted time zones to OS time zones.