Finally! I've spent the last age figuring out how to make a very rudimentary Debian package after pulling the latest ufraw source from CVS. I've now got a .deb file that provides ufraw and the GIMP ufraw plugin that incorporates the latest Nikon NEF encryption stuff properly!
I've attached it to this post as I've noticed that my entries are usually in the top five when searching for ufraw and D70S. I make no guarantee this will leave your system in a usable state but I can confirm it works well for me.
Last night I figured out how to get Nautlius to display the embedded (white balance encryption-free) thumbnails too, so I now have a better all-round solution than most Windows and proprietary Nikon software users do.
I'll have a go at playing around and maybe upload some photos shortly.