The time between now and then will be spent convincing developers to cook up innovative dual-screen experiences, though it's anyone's guess what those could look like. The closest analog available right now is Samsung's Galaxy Fold, which at best allows you to run multiple apps on a single display -- hardly any of Samsung's software feels truly tuned to take advantage of that single big screen. If nothing else, you can expect Microsoft's suite of very, very good Android apps to evolve as we get closer to the Duo's official release date.

While it's easy to look at it as just a (very interesting) phone, Microsoft corporate vice president of devices Panos Panay stresses that it's a proper Surface first and foremost.

"We absolutely know scientifically that you will be more productive on two screens," Panay said.

That focus on actually getting stuff done on multiple displays was the ethos Microsoft ran with last time, too. One of the biggest draws for its earlier Windows 10 Mobile platform was Continuum, which let users connect their Windows phones to external displays, augment them with Bluetooth keyboards and mice, and effectively get the standard Windows experience. While other smartphone makers eventually implemented their own Android desktop modes, the idea hasn't really expanded beyond its original niche.

Rather than cling to classic computing concepts, though, Microsoft is looking at where the mobile industry is moving this time. It'll be a while yet before we get a true sense of what the Surface Duo is capable of, but one thing seems clear: People will be more excited for this thing than they ever were for a Lumia.

Follow all the latest news from Microsoft's Surface event here!