In all reality right now now one would pay $20 a share for Pandora. I would be surprised if it would go past $12. At $20 a share you looking at around 3.3 billion for a company that hasn't yet made a profit. Just wouldn't make since.
Out of all of the potential buyers, I believe Yahoo is the #1 choice. Mayer is looking to acquire a media company and they will be outbid on Hulu. Given the market cap of P, it's more affordable and gets them in the music game without all of the development costs. If it happens, it will be before the end of the year.