Since there are no software or Isync plugins that currently work with this phone, here is a workaround.

First Backup your Address Book!

Next you must use MPT on a pc or virtual pc to Backup your data, not sync, which will create a folder called "MOTOROKR E6" or "MOTOROKR E6e" which is invisible.
Search for this folder, including invisible items, and copy it to your mac.

Inside the folder there is a file called "Contacts.vcf"
If you double-click on this file it will add all the contacts to your address book.
If you want to replace your entire address book, delete all your contacts first and then double-click on the file.

Theoretically, this should also work the other way around but I have not tried it so try at your own risk.
If you make a backup of your address book and call it 'Contacts.vcf and replace the file inside the folder on the pc, you should then be able to backup the opposite way to copy all the data from your pc (from the mac) to the phone.