I doubt this is something to worry about, but I had to check. I'm buying a WD MyBook Studio Edition 1TB and it will be sitting next to some speakers (Logitech Z-2300). I've seen speaker magnets mess up some TV's before (granted the speakers were way bigger), so I was wondering if this would be a problem. Thoughts?
The determining factor is if your speakers are magnetically shielded. I know my JBL creature II's are magnetically shielded. I looked at the link you posted for yours and i couldn't find any info on it. For a fact i know the logitech z5500's satellite speakers are magnetically shield but the sub is not.
Hope this helps
Edit: After googling around i've determined the sub is not shielded (one source) so as long as you dont put your hdd by you sub you should be fine with your drives