From the Skype Blog:
We are excited to announce the availability of an early, preview version of Skype for Windows Phone 8. In this Preview, you'll get all of the Skype basics in the new, modern design along with many of the new features such as integration with the People Hub and a combined contact list with buddies from Windows Live Messenger.
Plus, you'll start receiving some call and message notifications - even when the app is closed and in the background.
Download the Skype Preview