In the Office Update released on April 15, 2015, we released the new Skype for Business client via Windows Update and Click to Run. With this change, we effectively replaced the Lync 2013 client with the new Skype for Business 2015 client, and added the ability for administrators to choose between the existing Lync user Interface (UI) and the new Skype for Business UI.
On May 12th there will be another monthly update from Office and organizations that did not take the April Office Update will most likely pick up the May Office Update for Office 2013 ProPlus and Office 365 Pro Plus.
