Existing users, 
Isn't this basically the same thing that Apple gives us as an Applescript Example Mail Script for FREE? Allthough it's one way...
This script is intended for users wishing to import their addresses from
Entourage, Outlook Express, Eudora, or Palm Desktop into Mail.
The Entourage and Outlook Express importers have the option of importing
directly from the application (if you have it on your computer) or importing
a text file that has been exported from either of these applications. If you
choose the direct import option, more of your data (like groups and categories)
will be preserved.
Sync Entourage-Address Book (Jaguar)
syncs both apps
Version: 1.3.6
Apple includes this for free in OS X
Feedback Type: Usage Tip
Contributed by: Siskel & Ebert Sunday, September 28 2003 @ 12:39 AM PDT
Product Platform: MacOSX
Used Product For: Have Not Tried
Recommend Product: NO
Comments
Apple includes this for free in OS X - hEADcRASH
...for importing only, not for synchronizing.Monday, September 29 2003 @ 03:01 PM PDT
Apple includes this for free in OS X - cclauset
The scripts that Apple provides are designed for a one-way, one-time transfer of information out of Entourage (or other email clients) and into Apple Mail. They do nothing to allow you to move that information back into Entourage, let also maintain synchronized address books.Reply to This
Sunday, September 28 2003 @ 11:20 AM PDT