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No, there is not, and Apple has no plans to extend .Mac synchronization to Windows OS platforms directly. There is support in the synchronization framework for third-party data synchronization, and Microsoft has enabled Entourage to synchronize through it.
It is possible to exchange data with this framework using Outlook and an Exchange Server, in a number of different ways. You can set an option in the Preferences… dialog of the Address Book, for example, to synchronize contacts with Exchange. The Address Book also offers LDAP support.
You can install the e2sync plug-in to synchronize contacts and calendars using iSync, use other applications like snerdware's AddressX and GroupCal to synchronize contacts and calendars, or synchronize contacts with an external source like Plaxo or calendars with Google using Spanning Sync.
Which options you choose depend almost entirely upon your workflow, the Windows data environment you choose to synchronize with, the availability of an Exchange Server, and your willingness to purchase third-party applications.