Syncing itunes and amarok database

[Corrin Lakeland]

Hi all,
 
I have one music collection which I share with my wife. I have amarok on
my computer, it works great.  My wife has iTunes on her computer, it
works great.
I would like to avoid duplicating the collection on each computer,
mostly so a fix of ID3 tags on one computer gets transparently sent to
the other.
 
The problem I've got is that both amarok and iTunes store loads of
information outside the file's ID3 tags.  In iTunes' case, it is some
sort of flat file, and in amarok's case it is a MySQL database.  So, my
question is how do I keep them in sync? Currently I rsync --delete from
the mac to the linux computer which means the changes on the linux
computer get lost.  Is there any way to do things so I can change ID3
information, add lyrics, add artwork, etc. in amarok and have it show up
in iTunes?
 
I don't think DAAP is a solution because AFAICT it makes everything
readonly which would prevent my wife creating playlists.  However, if
there is a way of adding full read/write that might be a possibility.
Similarly, I don't currently have the repositories combined by NFS after
seeing what happens in iTunes if an NFS share is unavailable but would
be happy to share (in either direction) if that helped.  
 
Thanks for any suggestions.
 
Corrin
 
PS: I suppose Amarok 2 will work on the mac, so if I can't find a
solution I will try that out when it is released and see if it is good
enough to ditch iTunes.