WpFandora is a unofficial Pandora client for your Windows Phone. The app comes in two versions, a free ad-supported version and a $2.99 ad free version (WpFandora Pro). The music app is laid out nicely and as long as Pandora doesn't break their public API, the app ran smoothly.
I'm not a big Pandora user but WpFandora came across as a simple, easy way to channel your Pandora stations to your Windows Phone. WpFandora is definitely worth trying if you are looking for a Pandora client for your Windows Phone.