Who is blocking video Airplay for websites, is it Apple or the website?

Question

I have to think the reason I can't share video from most websites to my TV is not due to technological limitations, but due to either Apple or the website owners themselves deliberately withholding from us this functionality. The reason I think this is because I've found a way to trick Airplay and/or the website to share the first ~15 seconds or so of the video to my TV. If you have an iPad and an AppleTV, here's how to Airplay share at least a portion of video from a website that's seemingly non-compatible for video Airplay sharing:
1. On your iPad, go to any website with a video you'd like to watch on your TV (I tried it out on cnn.com).
2. Tap to play the video on you iPad2.
3. Tap to share the video to your AppleTV via AirPlay. Except for a few select sites like Vimeo and I think You Tube, you will see that you can only share the audio to your TV, not the video. I'm having you do these first three steps just to prove the video is not compatible with Airplay sharing.
4. Now go to vimeo.com and play a video. I'm not sure this works with every video, so try out this one (don't worry, it's rated G): http://vimeo.com/14853945 When I played it I had HD selected so HD was highlighted in blue. Tap to share to your AppleTV (you should in this case be able to share both the audio and the video).
5. Now go back to that same website you were at before, tap the same movie to play it, and then tap to share to your AppleTV over AirPlay. This time around, you'll notice that you can in fact share both the audio and the video to your TV. However, after around 15 seconds or so it kicks you off so you are no longer able to share that video to your TV.
I think that's interesting. Does anyone know why that would be? My guess is that it's because once you can share anything you want from the web to your TV, you might no longer need to receive any cable broadcast, and, as an example, if you watch CNN on your TV straight from the Web, CNN doesn't get any money from that, whereas if you watch over cable or satellite, they already have an arrangement whereby the cable/satellite providers pay royalties back to the various TV networks for the right to distribute their content to our televisions.
However, I think it's already possible to share anything from the web to your TV, even on an iPad, right? I believe that that digital AV adapter allows you to fully mirror whatever is on your iPad to your TV already, doesn't it? If that's the case, why bother blocking the functionality via Airplay when we already have the option via an HDMI hookup?
This is all very interesting to me. My stepdad thinks in ten years the broadcasting landscape will have totally changed the way we watch TV. Rather than pay Comcast or DirecTV to distribute your content, you will access your content through a tablet or other device which you would then have mirrored on your TV.
I think my stepdad's wrong. I give it two years. Two years from now I think many of us will no longer pay Comcast or DirecTV for our content, and aside from sports and news, there will no longer be a schedule for when a program is on TV. Everything will be on demand. It's pretty much that way now anyway for anyone who has a DVR.

Answer 1

Thanks for all of the commentary. I posted this before I received my iPad2. I now have an iPad2 and while I've successfully mirrored it to my TV, I find it useless for mirroring anything other than video (because webpages, etc. look like crap on the TV) and the mirroring only works about half the time, if that.
At least half of the time when I plug the digital AV adaptor into the back of my iPad2, I get nothing on the TV. I think this is because it's a really long HDMI cable (cuz who wants to have to sit right next to your TV?) and I run it through an HMDI hub because my TV only has one HDMI input and I need 3-4 HDMI inputs (one for my DVR, one for my AppleTV, one for my HD camera, one for my DVD player and one for my iPad if I want to mirror it, which I won't if it continues to be so inconsistent).