The mobile clients themselves are not there yet, but the documentation for the server configuration is now available. You do need to configure the Lync server environment before you are able to use the mobile clients, so it is really helpful that the documentation is available already.
To give you an idea of the required topology:
The following diagram illustrates how the Push Notification Service fits in with a Lync Server 2010 topology.
Other deployment guides have been updated as well.
Download: Microsoft Lync Server 2010 Mobility Guide – Microsoft Download Center – Download Details.