We just released the April 2005 update to the Outlook 2003 Integration API.
Download for the CHM is here:
The MSDN documentation should update some time in the next few days. When it does, you'll find it here:
Note that the date on the Welcome page will be updated from December 2004 to April 2005 when the updates go live.
Many thanks to Dmitry for some valuable feedback that went in to this update.
As always, let me know any questions/concerns you have with the documentation.