Windows Phone app for desktop allows you to sync songs, videos, and photos between your Windows Phone and PC. If you have added your media files folder to the Windows library, it will show up in this program under the "PC" tab. At the same time, contents of your phone are automatically displayed in the "Phone" section.
It classifies Music files into two lists based on Genre and Artist. You just have to select the required files and click "Sync". A separate tab for ringtones is given, but it only lists the songs on your PC, which can be converted to a ringtone.
I occasionally use this program to sync photos between my phone and PC. But I prefer to use standard tools to manually copy songs and videos that I need. The reason for this is that Windows Phone app for desktop doesn't allow you to search music using file-names; it only shows the metadata information.
Since there is no other program to manage Windows 8 phones, one expects more features from the app, such as the ability to access text messages, change phone settings, or install applications. Still, I love it for the neat and clean GUI.