I certainly agree the studios' lack of perceived control is likely to be a factor too, but Hulu aren't alone here: HTML5 isn't (yet) good enough for us at Justin.TV either.
However, Apple has a method of doing this with entirely standard HTTP and a few metadata files, as this is how you do adaptive bitrate content on the iphone: http://developer.apple.com/iphone/library/documentation/Netw...
The formats and methods Apple provides in the spec for the IPhone can be used for both Live Content and for adaptive bit-rate pre-recorded content.
I hope eventually the iphone http streaming spec or a derivative would get adopted into HTML5 :)
Also it may be better to adopt another streaming protocol for HTML5 because the Apple's protocol is not suitable for low latency streaming.
Well, they don't disclose what the patent is, but bleh, its just stupid to patent crap like that :(
Interesting scheme. I'm wondering if this same idea could be used by a client-side library to enable buffering and dynamic bitrate changes. It could also be used to dynamically insert advertising video content into the stream...