(UPDATE 2) As anticipated, RIM has launched its BBM Music service in beta. Built as part of BlackBerry Messaging, BBM Music is a "social music sharing and discovery service" rather than a traditional streaming or download portal. For $5 a month, users get unlimited streaming of 50 songs and can share streams those songs with as many friend as they want, as long as they are Blackberry subscribersas well. 

COMMENTARY:

Since music sharing is a two way street on BBM Music, the size of your library continues to grow as you add new friends. But since sharing tracks is more likely among those under 25 - who strongly favor iPhones and Android powered phones over Blackberry - it's hard to see how BBM Music will gain traction.

Plus, why pay not pay $5 more to get unlimited streaming from Spotify, Slacker or their competitors. Then there's the fact that Blackberry's market share is tanking...