This article quotes a lot of self-serving executives who run subscription music services predicting they will be the next big thing but haven't they been predicting that since about 2001 and aren't Rhapsody and its brethren already offering something pretty similar that is only mildly popular? Don't believe the hype.
The difference now is far greater access. With smartphones in everyone's pocket and TV boxes that connect to these services the whole thing becomes a lot more compelling.
As someone who doesn't work for any of these companies I can tell you there's truth to what they're saying. My Mog subscription has caused my iTunes spending to all but disappear.