ArsTechnica reports that Android TV, Android Wear and Android Auto won't allow hardware manufacturers to change the interface. The software will be updated by Google and manufacturers will only be able to add some apps and some hardware features.
"The UI is more part of the product in this case," said Google engineering director David Burke. "We want to just have a very consistent user experience, so if you have one TV in one room and another TV in another room and they both say Android TV, we want them to work the same and look the same... The device manufacturers can brand it, and they might have services that they want to include with it, but otherwise it should be the same."
Much like Chromebooks, the new Android devices will be frequently updated by Google. Even if you're buying a Chromebook from Samsung, HP or Acer, you're getting almost identical software and similar user experience, but slightly different hardware.
Back when the first Android phones were released, Google was more focused on adding features and APIs and cared less about user experience. Manufacturers had to create their own apps and skins to sell phones. This fostered a vibrant ecosystem, but also created problems: devices are slow to update, Google's guidelines are sometimes ignored by manufacturers, user experience suffers. Apple started with the user experience and added the missing features later, Android started with the features and improved the user experience later.
"The new Android projects Google talked about at I/O this year circumvent the [fragmentation] problem entirely by not offering that kind of freedom to OEMs in the first place. That might make it more difficult for them to differentiate their products from one another, but it saves them a ton of development work and gives users more consistent, more secure devices that all pick up new features at the same time," concludes ArsTechnica.
They're more like Windows Phone devices. Strict guidelines, consistent interface and branding.