Update August 2012:
With Amazon servers it is possible to stream videos for Flash and HTML5 video players. So you can view private protected videos on all browsers, mobile phones, ipads and other tablets.
More information: Private Protected Video with Amazon Servers
Amazon Cloudfront streaming servers with private URLs have just been online for a few weeks. Therefore there is not much information available nor are there many code examples.
Here are a few links to explaining websites and a working PHP code example.
I hope this helps some other developers 🙂
>>> Download Code Example: