We definitely agree with you that many users want to continue using Outlook in its' full functionality (they could already use it today with Zimbra, via IMAP for email only), and our Outlook MAPI connector is planned as part of the Zimbra Network version. It will indeed support full email/calendaring/contacts features. You can see details about the Network version of Zimbra Collaboration Suite here
What's in the Open Source Edition vs. Network Standard Edition
As for timing: the Outlook MAPI connector will not be available when the current version of Zimbra Collaboration Suite is officially released in a few weeks; but it will be available by late this year (exact timing
TBD).