Cnet has sources telling them that Google and Spotify are discussing the possibility of co-launching a streaming music service in the US. Considering the arms race Google is engaged in with Apple and Amazon to cloudify everything, this makes sense.
Spotify wants to launch their beloved streaming music service in the US, but seems to be unsure of a business model. Google wants a cloud music baby of their own, but seems to be inept at wooing the record labels. Each company's respective strengths seem to compliment each other. An unlimited streaming offering would allow Google to differentiate itself from Apple and Amazon. Meanwhile, Spotify would presumably be given the financial resources to compile and maintain a massive catalog of music.