I agree with many of the points Mike posted in his article. In my opinion music streaming and sharing is an experience to be used by a single user, shared with another user or with a group. Not sure if we want to be held hostage to being sucked up into permission based hosted services.
As these Social giants play on hosted solutions, I think it is worth it to look at a new birth of music experience and that is MyStream.
MyStream is a mobile to mobile audio streaming and sharing technology that allows one to One or one to many users the ability to share music in a private network.
The software turns each mobile device into a client and server and thaws guys are a small startup with a huge idea!!!
Check em out on: YouTube.com/mystreamapp. There are 2 video to see.
Product landing page is www.mystreamapp.com. App is currently free on iTunes AppStore and they are working on the Droid.
Be cool! Try it out and clearly they just started and will continue to build on the original concept.