This is a software limitation as the button form the original headset can, obviously, be used to answer calls.

If you read how this brainstorm started you'll see that nokia doesn't always add full headset remote functions depending on the phone.

For example N82 is a photo/geo tagging phone - why would you need music control via the default (5 button) headset

Note that such an app/applet greatly improves the experience for the current headset as well with the use of "gestures":

- single click: play/pause (answer/end if the phone is being used)
- double click: next track
- long press: voice dialing (when it will be available)

A similar applet has been designed before: http://talk.maemo.org/showthread.php?t=21182