Although Microsoft doesn't like to publically talk about its next-generation operating system, Windows 10X, it seems as though the company has made some big internal progress on it. According to Windows Central's Zac Bowden, Microsoft has apparently just complied a final build of Windows 10X.
Trying to confirm, but I believe the final build of Windows 10X has been compiled at build 20279. MS will continue to fix bugs internally between now and when the first 10X devices start shipping.
— Zac Bowden (@zacbowden) December 11, 2020
As a reminder, while Windows 10X was once intended for dual-screen devices like the now-delayed Surface Neo, but Microsoft has re-worked its purpose. Now, the operating system is believed to be shipping on new lightweight and budget PCs only, which are expected to be seen sometime next year. This means rumor still has it that Windows 10X won't be available for existing PCs or tablets like Surface Go 2.
Anyway, Bowden does offer an interesting note. December 10 was intended as the "final build" day for Windows 10X, but Microsoft isn't quite done with the OS just yet. The company is still working on bug fixes between now and whenever new PCs start shipping with the operating system onboard.
With this in mind, it definitely looks as though 2021 will be exciting for Windows. While the Spring might again bring a small regular Windows 10 release, we could see Windows 10X launch alongside it, on new devices. Then, in the fall, see the rumored "Sun Valley" redesign with the "Cobalt" update.