I have 2 of the older 3G VST drives that work great in OS X. Even pulled the drive on one and updated it with a 30G - sweet portable drive now!
Should be no problems at all - no drivers needed. I would note though - I am not so sure going back and forth between OS X and OS 9.x machines is a good idea with the drive. Seems to be some bugs in the Apple FW drivers between the two systems that can sometimes corrupt data. It won't hurt every once in a while - but I wouldn't make it a habit.