Hulu is rumored to be working on an app for the iPad. In reality, they have never made an announcement, and it would be a pain since the iPad doesn't support the video formats that hulu's content is encoded to.
Netflix already supports many devices where it makes more sense to stream, like set-top game consoles and internet connected TV's and Blu-Ray players.
Hulu would be stupid not to convert or offer the other codec. And they know it. Flash, at least for video, is not going to last. It’s buggy, bloated; I hate it.
And seriously,a software conversion program that runs in batch mode, is not all that difficult to do. And requiring that new submissions are to support it would be in order.
This device is going to alter the video presentation Format on the web. Of that I have no doubt.