AirPlay Is Coming to Apps, Except the Ones You Use

iPad and iPhone users will soon be able to stream video from their apps straight to their Apple (s AAPL) TV, thanks to an update to the AirPlay feature that’s going to be rolled out with iOS 4.3. The new feature was announced Wednesday by Apple VP of iOS Scott Forstall, but what Forstall didn’t mention is that many major media companies aren’t likely to support the feature anytime soon.

In fact, if you’re looking to get additional TV content on your television via AirPlay, you’ll be disappointed. Hulu’s iPad app won’t support Airplay for the time being, and Comcast (s CMCSA) and HBO (s TWX) also are on the fence. Netflix, (s NFLX) which is usually keen on supporting as many platforms as possible, isn’t interested in AirPlay — and don’t hold your breath for AirPlay becoming part of the ABC (s dis) app.

There are a number of reasons for big media to stay away from AirPlay. For Netflix, it’s simply common sense. “Netflix is already available on Apple TV so we aren’t planning to support AirPlay,” Steve Swasey, the company’s VP of communications, wrote via email. The company simply isn’t interested in reinventing the wheel to get the service on a device that already carries it.

In the case of TV networks like HBO and cable providers like Comcast, though, it’s a little more complicated. Spokespeople for both companies said it’s too early after the announcement to say whether they’ll eventually support AirPlay, but an HBO spokesperson said there are internal discussions happening around the subject.

The reason for those discussions is that virtually all broadcast and cable networks have broad policies in place to make sure their web content doesn’t show up on TV screens. That’s the reason the networks have been blocking Google TV (s goog) products from accessing their content, and it’s the reason Hulu needs separate licensing agreements with rights holders to display their videos through Roku boxes and similar connected devices.

Of course, that doesn’t mean none of these media companies will ever support AirPlay or similar features. Hulu, for example, only offers iPad users access to its Hulu Plus catalog, for which it already has the rights for various devices. Comcast is also looking to get its TV Everywhere content directly on connected devices, and the company demoed its first app for Samsung TVs at CES.

However, Comcast might still face resistance from rights holders for embracing technologies like AirPlay, and overcoming these roadblocks could take time. And during that time, Apple may enable content providers to create native apps for Apple TV, once again taking away the need to support AirPlay.

The only major media brand we talked to that actively plans to support AirPlay right away is the online music video distributor Vevo. “Vevo’s iPad app was just updated to support AirPlay & iOS 4.3,” Vevo CEO Rio Caraeff wrote via email. The new iPad app is already available in the app store, and an iPhone version has been submitted to Apple and will be live shortly. The reason Vevo can move quickly while others hesitate is all of the content on its site is licensed for all digital platforms. “We knew at the very beginning that everything would be connected to the Internet,” Caraeff told me a few weeks back.

Of course, big media’s concerns about AirPlay are largely being rendered irrelevant by the fact that the iPad now also supports HDMI out via an adapter that’s sold separately. iPad owners using the adapter can watch any video they want on their TV — but for media companies, it may take some time to get comfortable with this kind of blurring of device boundaries.

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