My Pioneer DJ-500II cd player was already capable of doing this about 4 years ago when I bought it. Though it has a 10% up/down pitch, the "master tempo" feature (as they call it) is only usuable up to +/- 7%. If it gets pushed more you start to hear it. It's not very obvious, but if you listen closely you'll notice there's something about the music that isn't quit "right".

On a sidenote, the latest product in this series is the DMP-555, which even allow playing (mixing) mp3 cd's! Too cool!