If I saw someone boasting that their camera has these features, I would laugh in their face. Yes, I would. It's not like you can record images while the music is playing and have a lovely soundtrack, because it doesn't work that way. No sweet, sappy, love song will be in the background of the wedding toasts (unless there are musicians). The camera mic probably couldn't take it, you wouldn't hear any of the extended action, and the camera won't let you (at least not the one's I've seen.)
Honestly. How often could anyone even have the opportunity to use those functions? "Oh honey, I'm going out for my evening jog. Have you seen the headphones for my camcorder, I want to listen to some tunes."
Seriously, if you want an mp3 player... get one. If you want a radio, get one. But don't listen to either on your digital camcorder. It's not even remotely what it's made for! It'll just eat up your batteries, which you'll then throw away, and pollute the Earth with more than just your idiotic technogasms.
Christ. Next thing you know they'll be putting mp3 players into cordless power tools, graphing calculators, and electric toothbrushes... *facepalm*