That sounds absolutely absurd. Why would I want my music to change tempo? The whole point of having a song in a playlist is because of it's intensity and the mental state it puts you in.
I can just imagine listening to my favorite song being "conducted" by my running pace. One second it sounds like
Alvin and the Chipmunks and the next minute it sounds like a
Teddy Ruxpin Doll with worn out batteries.
STUPID idea. No moron would ever use that feature. NOT EVEN FOR TECHNO.
Why does Apple do that? Why not something good like a GPS feature that actually does SOMETHING.
I love my Apple Computer. I have loved all of my Apple Computers... even the Newton... but man does it get hard to defend stupid stuff like this.