As far as I know, Netflix does not handle the actual streaming of bits - it is done by CDNs like Akamai or Limelight.

They have been moving a lot of their infrastructure over to EC2: http://www.zdnet.com/blog/btl/netflix-migrating-more-infrast...

Netflix is using Level3 as their CDN to stream movie - http://www.thestreet.com/story/10916915/level-3-surges-on-ne...