While waiting for Microsoft to release mobile clients for Lync, there now are some alternatives available.
Audiocodes Mobility Plus definitely looks promising.
Damaka is a company demonstrating video calls between an Ipad2 and Lync on their homepage.
There is also an unofficial mobile Lync client for Windows Phone 7 available.
(With a little Niklas included! :-)
Please comment if you have any experience with these solutions!