To be honest, i'm perfectly fine with that. Since the acquisition of Skype by Microsoft, they've had 2 separate communication applications running/developing concurrently. By discontinuing one of them, they can focus more attention on the other. I've got my Skype integrated with both Facebook contacts, and MSN contacts. I haven't had WLM installed for well over a year now.
To any new Skype users migrating from WLM: Upon launching Skype, you are offered the ability to login using your WLM credentials, and it will store all of your contacts. Due to the nature of Skype, you end up gaining new functionality, so long as your contacts are also running Skype (such as voice chat).