Alright... there's a bunch of solutions out there.
You can drag and drop your iTunes Music folder into a folder on the sd card.
You can use DoubleTwist. The one time I used it, Doubletwist and my found hung forever.... had to pull the droid out to use it.
There's iTunes Agent. Haven't used it yet. And Motorola Media Link. Also haven't used it...
Anything I'm missing?