Microsoft today released the Mobility package for Lync 2010. The Mobility package along with Cumulative Update 4 allow for the Lync Mobile Clients to connect. From the Mobility document:
The mobility feature in Lync Server 2010 supports Lync functionality on mobile devices. When you deploy the Microsoft Lync Server 2010 Mobility Service, users can use supported Apple iOS, Android, Windows Phone, or Nokia mobile devices to perform such activities as sending and receiving instant messages, viewing contacts, and viewing presence. In addition, mobile devices support some Enterprise Voice features, such as click to join a conference, Call via Work, single number reach, voice mail, and missed calls.
In addition to the Lync Mobility service, Microsoft also released the Lync Autodiscover Service which allows mobile applications to locate the Lync Web Services without requiring users to manually enter the URL in their device settings.