Microsoft has released Skype 6.3 for Windows and Mac OS X. Despite identical version numbers, both versions are different with their own features and improvements.
The Windows version is a maintenance release but bug-fixes but the Mac version gets a some new features like an in-call DTMF dial pad. Mac users can also view a slideshow of other participants in a group call when the user is the current speaker.
Screenshot of the dial pad:
Changelogs: