Fair warning to Mac Users.
If you already use the Zimbra iSync Connector, you will be bitten by this bug when you sync your TB.
Bug 21738 - Change of a contact's primary email address in iSync Connector.
Luckily, this will only be an issue if you want the contacts "work" email address to be primary email address. If you are using it for home and have everyone's home email address, you'll be fine.
If only we could get Apple to move to the email/email2/email3 scheme instead of home/work/other, we would be all set.
