After a multi-year litigation battle between EMI and MP3tunes, a ruling was recently published and a winner almost declared. Due to outstanding issues and appeal possibility for both parties, it is not yet a full victory for cloud music and MP3tunes (although it is very close).
Michael Robertson - The Judge found "MP3tunes did not promote infringement." (page 18) which is important to note. We've always operated our music service in a responsible manner and because of that the Judge determined that MP3tunes has protection under the DMCA as a service provider for both MP3tunes and Sideload.com which is a music search engine.
Digital music providers like Amazon, Google, and Grooveshark will surely have renewed confidence in offering similar unlicensed services. However since it is not a final ruling..
Source: Michael Robertson