The problem of using a phone as an MP3 player is that the camera serves a very important function as an emergency device. Would it be ironic that as a person wants to call 911 or someone on an emergency, they found out that their phone does not work because the battery had died from using it as an MP3 player?

This is where combining music players (which are continuously played) and phones make little sense. I don't like playing the Java games on my cell phone becaus of this issue. It is better in this circumstance to have two gadgets rather than one.