Today at Build it was revealed that Notification Mirroring and Universal Dismiss are coming to Windows 10, Mobile, and Android devices. The service is an upgrade to the Windows Notification Service (WNS) and, for now, will work through Cortana, but later will go through the OS.
The news was revealed in a session entitled 'Notification Futures: Action Center in the Cloud and the Windows Notification Platform' and details about how the Notification Center is moving to a Cortana-MSA mediated system.
The new app feature will let developers add the ability to dismiss a notification across all devices universally. For instance, you could be on a PC and receive a news alert. Using 'universal dismiss' will remove that app notification from your phone and vice versa.
Notification Mirroring (showing notifications from one device on another, e.g., a notification on your phone then shows on your PC) works automatically without any changes to existing apps, and universal dismiss can be added by developers with one line of code. Developers have the choice not to use them, but Microsoft is encouraging developers to enable the feature as obviously it could prove to be very popular.
Likewise, users too can opt in or out of the feature as well as mute notifications through settings in Cortana or within the app itself.
The function only requires a couple of lines of code and is very simple to implement. Since there is not cost either the barrier for developers to enable this feature is super low.
For now, Cortana will be used for a faster deployment, but later Microsoft will hard code the linked notification support in the Windows 10 and Mobile OS.
Microsoft is looking at bringing the feature to iOS too, but it is more difficult due to the OS being more locked down.
Unfortunately, no timeline was revealed and instead is referred to "future versions of Windows." More details will be announced in a blog post following Build.
Update: Microsoft has now posted the video of the Notification panel on the Channel 9 site.