CopyNex is a utility to copy files to the NexII MP3 Player. While the NexII and NexIIe do not require the use of extra software to copy files over (they just use a normal CompactFlash card), they've got a bug in their filesystem handling and also don't recognise Winamp playlists. If you use CopyNex to transfer your music (either directly to the player or on to the memory card with any other CompactFlash drive), the Nex will play them in the intended order and you can get fake playlist support.
The current version is CopyNex3 "Final", now tidied up and packaged with a nice installer. Oh, and now Open Source under the Free Software Foundation's GNU General Public License. At the current time I can't say if this tool is useful for the new NexIA player - I either need to get my hands on one for a bit, or get someone who has one to do some specific tests for me. Feel free to try it - worst case scenario is it just doesn't work.