There's a document on that page referring to MapPoint 2002.. here's the direct link:
http://download.microsoft.com/downlo..._2002_VPAT.doc
Not a great deal has changed between 2002 and 2004, arguably the primary value of the new version is the updated data... the interface and programming object model barely changed at all.
So, I'm sure practically everything in the document above is still applicable and valid for MapPoint 2004.
Eric