Today was the day that Office, arguably one of the most important elements of Microsoft's Windows 10 Mobile vision, moved officially out of 'Preview' mode and into full existence. Around six weeks before the platform is scheduled to be fully ready, this was a necessary step, of course. I can't even say that I noticed new functionality, but there's screenshot proof below of the change. 

Of course, everyday consumers may not be heavy Office (Mobile) users, but a huge thrust of Microsoft's vision for the platform is into enterprise, as quoted here, so a fully functional and official Office version was a prerequisite.

Here's my Start screen this morning on one of my Windows 10 Mobile test devices, and then checking the Store:

And here's the same set of tiles after the updates:

You'll see that all three Office applications have now dropped the 'Preview' in their names. These universal applications have been fairly mature for a while, to be honest, since they've also been tried and tested on the desktop/tablet, so it's not entirely clear why it took Microsoft so long to drop the 'Preview' tag. (Mind you, Google Navigation has been in 'beta' now for a decade, so who knows what goes on in these big companies!)