Currently, this is using data returned from one of a number of sources (they are currently in various states of development):
Thinking about how to leverage the work being done with Playdar's resolver framework and plug-ins.
Screencast: Convert XSPF playlist without media links to RSS with MP3 enclosures
You give it an URL to for an iLike or MyStrands playlist and it will go and try to rebuild it using free-range MP3s. Why? Well, I started with those two services because their client software (iTunes/Winamp/etc.) plug-ins can automatically publish your playlists from your media player to the web. Since most people make their playlists on their desktop, this cuts out the step of having to manually recreate it on the web so you can share it with others. Also, it lets you leverage any other "playlist builders" (e.g. Apple Genius) on your local machine and then publish those machine generated playlists too.