You want to give your listeners a broad range of music. Some artists wanted to withhold some of their songs and not have their music on "internet radio". Pandora won the case so that group of artists can't withhold their music from Pandora.
The deal is that the music companies can't pull out of the deal they currently have with Pandora. That's a bad sign when they no longer want to deal with you. Either way, rates are going up under the current deal through 2015 when the deal expires. Do you think rates are going to go down after that. I wouldn't. Not with Apple paying more and giving them a piece of the advertising revenue. Also, by then, Pandora will probably have less listeners and even worse bargaining power. At that point, Pandora, with its high market cap and executives making huge amounts off their options, needs the music industry far more than the music industry needs Pandora.