(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.
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...