Basically what I'm after is for someone to write a patch for XBMC (an open source media player, source available on github) which enables timestretched/temposcaled, same-pitch audio when using the fast forward/backward function. It should be as unintrusive and minimal as possible so as to work with future versions, so it needs to be coupled with the existing FFW/REW function rather than have a seperate interface.
You can see some of the responses from the XBMC-Team on adding this feature here
[url removed, login to view]
which makes it unlikely that it will be added even though they seem to be reworking the audio-engine atm.
Apart from coding it, I'll need you to show me how to apply it for future builds (OSX).