I am shooting a music vid tomorrow at 720P - I was gonna shoot 24P but an editor said to shoot 30P - he said that is easier to work with for music videos.
Ironically, the great majority of music videos made in the last 15 years have all been shot on film. I think 24fps would be more than appropriate for a professional looking music video.
I also think that music videos are great for experimentation. I'm doing one in April and I plan on really messing with the shutter and the frame rates of the video.. as well as the audio. I'm really looking forward to the experiement.