Hi Thomas,
It will probably depend on when Dave Coffin adds it to dcraw. There are only a few raw converters that can handle X3F files, many depend on dcraw. I've only tried acr and Sigma pp4. The Sigma program appears to give better results than acr, but for me, using win XP, it often crashes. However, if you want the ease of Qimage raw image manipulation, then you could use acr or whatever to convert the x3f to a linear dng file -
http://en.wikipedia.org/wiki/Digital_Negative_%28file_format%29 -, and you can open that in Qimage as a raw file.
Best wishes,
Ray