It offers access to all tiers of the service: free, Pandora Plus and Pandora Premium. You can use keyboard shortcuts to control playback and see notifications that detail the artist, song, and album title for whatever you're currently playing. You can also use the Pandora Modes feature, through which you can customize the kinds of songs you hear on stations.
However, it seems you won't be able to play podcasts through the app just yet. Podcast support should arrive later.