Yes of course we have thought of this, it is an obvious idea. However the implementation would be somewhat involved compared to the current implementation. Imagine you are currently playing an MP3 and you want to scan another track (or the one you are currently listening to). This would not only require running 2 simultaneous decoders at different speeds, but also would require modifications to the existing user interface so that you could select the tracks to be profiled.

Nice idea, but unlikely to get implemented in the near future. For the moment you'll just have to leave your player 'scanning' overnight if you have a backlog of stuff to get through.