New Spotify users will now require a Facebook account to join. From Get Satisfaction’s Spotify page:

Hey Guys thanks for your question, Unfortunately you will need a Facebook account to access Spotify from now on, unless you already have an account set up.

This does not stop you creating the Facebook account adding nothing to it and making it totally private as the Facebook account does not have to be actively used.

Makes me wonder if this was a condition to allow Spotify to integrate with the new Facebook features.

There’s always Rdio for those against having any association with Facebook.