*** 10/18/2013 Update: This has been resolved with the latest updates to the mobile client. ***
I was recently working with a customer and they asked if I had heard anything about Lync 2013 mobility client video being garbled on iPhone 5s with IOS 7 (see below). At the time I hadn't but after some research found that other customers were experiencing the same issue. I wanted to confirm this was an issue with some of my customers and sure enough it happened on every iPhone 5s with IOS 7 and the Lync 2013 mobile client. This is known by Microsoft and has been escalated to our SEE's for further investigation. This seems to be speicifc to the iPhone 5s because I have tested iPhone 4S, iPad 3, and iPhone 5 with IOS 7 and they all worked fine. Once a resolution is reached I will update this post.