Hulu DOES block access from mobile handsets though. It will be interesting to see where content providers end up classifying the iPad. Is it a computer? It's about the size of a subnotebook/laptop, certainly not a handset. But it runs a mobile OS... so which is it, in regards to licensing agreements?
The thing about Hulu, though is that it's owned by the same companies who own the distribution rights to the content, so even if they decided the current rights don't allow for an iPad app, they could, with far less trouble than other companies offering similar services (Netflix, for example) simply modify their arrangement to allow that type of app.
I think we'll start to see some of the streaming sites come to the iPad/Phone sooner or later. It's only natural... and if they don't Apple might[/t] beat them to it. How long before they get a deal to offer some sort of unlimited streaming rentals via iTMS? If they get there first, it might be hard for other companies to get a foothold in that market later.