backing up the content on the iPod is possible.
you have to [http://support.apple.com/kb/HT1535|manage the content manually]
after you've done that - you can access the iPod in finder/windows explorer
open the "drive" that is assigned to your iPod and then go to "iPod_Control\Music" - there are folders called F00, F01 - and so on.
in those folders is your music - but the files faf names like CHLD.mp3, EXFL.mp3 and so on - this is not a problem, itunes ignores the tintle of an mp3 - it only uses the ID3 tags inside the file
you can simply copy those files to your computer - but be aware - copy protected files will still have the DRM stuff in it