The short answer is you cannot current watch Netflix on a Raspberry Pi. There's some debate as to why, as many people would be interested in streaming Netflix or Hulu on their device.
The two main theories for why Netflix cannot be watched on a Raspberry Pi is:
1) Windows doesn't want to support Silverlight and a DRM on Linux out of principle. They are competitors, and there's no reason for Windows to dedicate resources to make that happen.
2) It could also genuinely be down to the fact that the Linux DRM isn't secure enough, and Netflix are worried about providing users with easily copyable streaming content.
