I've been using Banshee for my music listening needs the past few months after using iTunes for a very, very long time. I never got around to importing my iTunes playlist, mainly because there weren't any good solutions when I first looked into it a few months ago. This weekend I finally imported all of my iTunes info (play counts, playlists, ratings) using a great script found here.
However, it didn't work for me right off the bat. For some reason, the file size in my iTunes library didn't match the file size reported by Banshee. Also, the database format appears to have changed slightly since the script was originally written. Here is a copy of the modified script, which just has two changed lines of code. Hopefully this is helpful to somebody and be sure to thank the author of the original script if it is!