this is one that I would really love.
You can do this in PT, and it really helps with AAF imports that usually contain split stereo files.
I know you can convert split stereo to stereo interleaved, but as soon as a fade or edit is slightly off on one track it will not work anymore. I end up using two linked mono tracks panned hard left and right (emulating split stereo), but then if you search and drag something from the media bay or pool it will only drag the left side across (a major PITA)
I think there is room for improvement