No longer do I have to find the browser tab that Pandora is running in to pause it, or to see what the hell it is I'm listening to. Nor do I need to worry about Flash crashing.
It's also extensible in that it can call out to an external program for various events, such as starting a new song. This makes desktop notifications of what the hell you're listening to trivial.
It'll also read commands from a named pipe, so at work, where I have this crazy Microsoft Natural Keyboard with all sorts of multimedia keys, I've set up evrouter (which isn't in Debian for some strange reason) so that I can pause, skip and like/dislike using my keyboard (regardless of what application I'm in). So I can just kick off pianobar in a terminal somewhere and forget about it. This is so cool.
Interestingly, it also doesn't play any advertising, so I've finally pulled my finger out and paid for a Pandora One account.
Overall, this makes for a fantastic desktop Pandora client. Now I just need to figure out why I get weird HTTP errors from it at home...