I had the same question myself.
The widget owner (Hulu) decides what content is available for streaming, and what's available for regular computer watching. There is a difference, as - as far as I'm aware - not all video files are, at this time, available for streaming.
There isn't a separate App for the other videos.
Hi, I just purchased this TV (UN46C6500VF) and it has Samsung Apps with Hulu Plus.
But the content I want to watch is on regular Hulu. Is it possible to watch all Hulu content with Hulu Plus? Or is there an app for regular Hulu available?