Not surprisingly, the Skype crew is eager to avoid any legal trouble in areas where recording demands mutual consent. Everyone involved in a call will know when you start recording, and the app encourages you to tell other participants if they are not already aware.
The feature might not matter so much if you just want to remember what your friends said in an ordinary conversation, but this could be helpful to virtually anyone who wants to broadcast conversations. Many of them use Skype, but they often have to run separate recording apps (or even a separate device) just to ensure they have a hard copy. This puts much of what they need in a single app.