Skype 7.1 for Mac not only supports Mac OS X 10.10 Yosemite, but it also has better group profiles, and a couple of crash fixes. Microsoft has also updated Lync for Mac 2011 to version 14.0.10, adding support for Mac OS X 10.10 Yosemitie, media resiliency, and conversation history.
First, if a network disconnect occurs, Lync for Mac will now automatically rejoin a meeting or reconnect a peer-to-peer call as long as network connectivity is re-established within 30 seconds.
(Try it for yourself. Setup a Lync video call on your Mac. Quickly disconnect and reconnect your network cable, or disable and re-enable your wireless connection. You’ll see the video freeze when the network drops and then restart once connection is re-established.)Second, Lync for Mac will now maintain the media connection for peer-to-peer calls if connectivity is lost to Lync Server or Lync Online. This lets voice calls continue even when presence information is no longer available.
Lync for Mac 2011 version 14.0.10 also has conversation history that is actually saved in Exchange. Perhaps the biggest advantage of this is that if a user chooses to save the history on Exchange, they can access it from different Mac computers either for work or for personal use.
Refer Skype Blog [Skype 7.1 for Mac]
Refer to Office Blog [New Lync for Mac adds Media Resiliency, Conversation History and OS X Yosemite support]
Download Skype 7.1.665
Download Lync for Mac 2011 v14.0.10