Afternoon,
Starting Point, my specs: Mac OS X 10.5.5, iTunes 8.0.2, Jaikoz 2.8.4.
So I finally sit down with some hours to play with the music, time to work out how to export from iTunes into an m3u format so that I can load a playlist in Jaikoz!
So I found “Export Playlist to M3U” a little MOSX application that will create a *.m3u file from whatever playlist is selected in iTunes. You go into iTunes, select (touch) one of the playlists there, and jump back out to the finder window, open this application, it does a quick jump to iTunes, then pops up with a window asking where to save a *.m3u file of the name of the playlist from iTunes.
A *.m3u file is essentially just a list of file paths. This particular application generates a list of filenames with absolute paths, so:
Jaikoz sees that its a .m3u, it “imports” it, but nothing happens. 0 songs. But the playlist exported has around 350 tracks in it.
OK, so I do a little reasearch, Winamp has an “Unofficial M3U and PLS Specification” on their faq. Alright, I’ll edit the file to make it relative paths, so placed the m3u at the same level as iTunes Music Library, and I remove the absolute path prefix of /Volumes/HDD/folders/ from the front of every line in the textfile (used excel import and just Fixed-Width chopped it into two columns) anyhow, so now I have a .m3u file with a series of filepaths based on the current location of the .m3u file… Import… 0 songs. Dang! 
Next Effort, maybe the m3u format doesn’t like *nix filepath syntax, the slashes may be in the wrong direction… search and replace ‘\’ for ‘/’ … Jaikoz, point it at the new .m3u file… WINNAR!!! 349 tracks loading!
So .m3u is a Windows format (duh in retrospect), but the basic script I exported from Mac iTunes simply took the local path entry and made a list of them, and well, those local path entries are in Mac path formats. So I suppose the file I was trying to import therefore wasn’t really a m3u file by specification.
So in summary, a way to use the import playlist function in the current (at time of posting) v 2.8.4, use “Export Playlist to M3U” , save it in the same location as your iTunes Music Library folder (mine is not in my user directory/Music), chop off absolute pathing to make it relative, and then search&replace the \ for /.