It appears that Microsoft has signaled the death knell of Windows Phone. In its big Windows 10 press event on Tuesday, Microsoft has announced the arrival of Windows 10 to all of its devices, including smartphones, tablets, and PCs. The OS will scale depending on your type of device and eventually replace the Windows Phone OS used on smartphones today.

Since 2010, Windows Phone has been slowly making its way in a market dominated by the likes of Google and Apple. Microsoft’s VP of Windows, Joe Belfiore, announced that Windows 10 will come to Microsoft’s smartphones as part of a plan to unify the Windows experience on as many devices as possible. Not much is known yet about how this OS and its design and features will differ from the current Windows Phone 8.1 experience. At the very least, Belfiore noted that “We’re trying to blend the experience across PCs, tablets. The best way to think of it, it will be a natural step forward from the Windows 8.1 model.”

While Windows 10 has been previewed with a number of big changes for PCs and tablets running the x86 version of Windows 7 and 8.1, we don’t know exactly how Microsoft will change the mobile experience. There will be a merger of the Windows Phone Store and Windows Store, with emphasis on developers being able to bring their apps to as many devices running Windows 10 as possible. Microsoft isn’t making the Widows 10 experience identical for each device either. Depending on whether your screen size is four inches or 40 inches, it appears that the Windows UI will scale its start menu and other features to ensure you and your fingers can click whatever ends up on your screen. Microsoft will (thankfully) not be bringing the desktop to smartphones.

Microsoft hasn’t shied away starting anew with Windows Phone in the past. In 2012, the Windows Phone 8 update for Windows Phones broke compatibility for not just Windows Phone 7 devices, but also many of the apps running on the older OS. The team now working on Windows 10 is different from the one that has been developing Windows Phone. However, we don’t know what ideas are in the works and when we’ll see a test build of Windows 10 designed for smartphones.

We’ll keep you updated as we learn more about the future of Windows Phone as it integrates into Windows 10, as well as what features will come with the future update.