Yes. The sales tax consequence to amazon is huge. I really don't know why these rumors keep popping up every couple of years. Perhaps it's because Werner Vogels spoke at our weekly tech talk thing?
I don't know that this makes the Netflix rumor any more likely, but you can't just dismiss it based on sales tax implications.
http://kara.allthingsd.com/20090714/amazon-buys-netflix-micr...