Microsoft released the Lync client for Mac;
Bits are not available for download on the site yet but should be coming soon (Enterprise Customers can get the download on MVLS or MSDN).
Lync is one of the best telephony/conferencing applications out there and I have been waiting for the Mac Version for a long time. If MS would finally release the same Outlook version on the Mac as for Windows I could get rid of my virtual Windows machine (I guess I just discovered why Microsoft DOES NOT provide the same Outlook version for Mac…).
Anyway – Client works great. I just hope for a decent iOS Lync Mobile Client supporting Audio/Video.