After months of testing, speculation and preparation, Microsoft has removed the "Preview" tag from their Office apps in the Microsoft Store. This may seem like a small step but it's a clear signal that the only ways you'll be able to buy Microsoft Office in future will either be as part of an Office 365 subscription or by download through the Windows Store.
When Windows 10 S was announced last year, these apps were made available in beta form, mainly as a way of showing how complex apps can be ported from Win32 architectures using Desktop Bridge rather than the Universal Windows Platform (UWP).
That journey is complete although you'll notice OneNote hasn't been given the Desktop Bridge treatment - it's coming across as a UWP app. Presumably, that's because of it's different user experience and multi-device capability. And there's no sign of other productivity tools such as Visio and Project which are critical apps for many users.
It's pretty clear the world is fast leaving behind the idea of buying software from resellers. While there will remain a strong market for people selling bulk licensing, particularly as software licensing is still too complex because software makers continue to use confusing arrangements that frequently change, it looks like future Windows users will be buying their software online through apps stores.
Enterprises will still need folks who can understand and negotiate licensing deals but, for the masses, it's going to be easier to enter into a subscription arrangement or purchase a perpetual license through an app store.
While many hate subscription services (and the way they can pile up and trickle the funds from your accounts), they make it easy to ensure you're using licensed software. And while the next version of Office will still be available with a perpetual license, there's no guarantee the one after will.