Developer-wiz Koushik Dutta of CyanogenMod has made a bit of a discovery in the Android 4.4.1 patches.
It looks like Google is preparing to add Android mirroring to Chromecast in the near future. However, Dutta pointed out that the API isn’t available to anybody except Google and the OEM. This essentially means that developers won’t be able to tool around to come up with new ways to integrate the feature. Similar solutions like Android mirroring on Chromecast won’t be able to be built into things such as Apple TV.
The API could become available to everyone in the future, but for now we’re pretty much left in the dark.
Source: +Koushik Dutta