Thanks for posting this - very helpful! I just finished using MediaMonkey to get my music from itunes to the G1. A couple of other things I'll mention that were useful for me. I used to scripts to add on to MediaMonkey to get my itunes playlists and to add batch album art in MediaMonkey. Scripts are here:
http://trixmoto.net/mm/scripts.php?id=1
Also I had a fair amount of trouble with album art showing up. Two things that made it work - Once in MediaMonkey, I had to convert all the itunes files from AAC to Mp3's. Then once they were in the G1 the artwork would still not show in the album view until I went to the songs view first and played a track off the album.
All is well now - thanks again for the help.