Applications for Windows Phone OS is designed by using the Metro Style and have access to core Skype features such as desktop version. Core features, among others, calls using 3G networks, video calling and calling to the phone.
Although Microsoft released is still in beta but the site of The Verge not find any problems in running the Skype app. In the following video you can see the performance of beta Skype app on Windows Phone:
News, Software, Windows Phone