Skype 5.8 for Mac is released with support for upcoming Mountain Lion and also includes the old slim look of contact list, and group screen sharing better.
Another enhancement of Skype 5.8 for Mac is better support for video calling from mobile devices and now it can also adjust orientation in landscape or portrait mode.
So, just download Skype 5.8 for Mac and give it a try to experience its new enhancements.