I don’t think that the iPad will ever get Adobe Flash. It’s not a matter of technical feasibility, but I think that Apple will ever allow it. The fact of the matter is that Apple manufactures hardware devices and sells the content to go along with it. Apple would cannibalize its content sales if they allowed Flash on the iPhone OS.
Why would any rational customer pay for a TV show or movie on the iTunes Music Store over watching it for free on Hulu? Personally, I don’t mind the small commercial breaks, and it’s totally worth watching shows on Hulu. Content providers probably feel the same way. I’m sure that they make more money on an iTMS download than a user view on Hulu.
YouTube has started to embed ads in videos now. Thanks to Flash, these ads are very easy to integrate in the YouTube video player, and Google can ensure that users see the ads when videos play. It’s probably the reason why YouTube has finally been able to turn a profit.
Recently, YouTube has allowed users to opt-in to playing videos with HTML5 support. It has that beta behavior, but I’ve tried it in Safari and Chrome, and it works pretty well. It’s nice, but I think that YouTube will stick with Flash for a long time. If Google permanently switched to HTML5 (Wikipedia link), it would alienate a huge number of users (sadly most people still run some version of Internet Explorer).
It would also be hard sell for advertisers to pay YouTube. Flash has a great way of insuring that a user sees an ad. If they switched to HTML5, the burden of playing the ad moves exclusively to the client. If YouTube relied on HTML and JavaScript to deliver ads, someone could easily create a GreaseMonkey script or bookmarklet to skip ad playback or block the ads.
Don’t get me wrong. I really like a lot of the features that HTML5 is going to bring to the web. Local client storage, easy video playback, CSS3, and the like are going to be amazing. It’s going to gain a lot of traction, but it won’t be in YouTube.