Sometime back Google launched music locker service (Google Music) where you can upload all your music to the cloud and listen to it from anywhere.
I could not have the first user experience as it is limited to USA. While browsing through the Demo video, I had the feeling that the Pandora is next in line to be acquired by google, just like Riya/Like.com for improving image search.
Google Music also seems to be integrated part of Google Docs.
Pandora : www.pandora.com
Google Music: music.google.com
Google Magnifier: a music discovery service. http://magnifier.blogspot.com/