Microsoft is adding native support for 3D printers to Windows 8.1. That means you don't have to jump through any hoops to 3D print an item — if your computer is hooked up to a 3D printer, you can just hit print.
There have been some rumours floating around that Microsoft would release its own affordable 3D printer, but that's not happening now. What is happening is Microsoft is partnering with a number of existing 3D printing companies — Makerbot, 3D Systems, Form Labs, and many more. Got a Replicator 2, for example? Or one of 3D System's adorable Cubify machines? You can print things right from your Windows machine.
Microsoft is announcing this news today at the Build Conference, in hopes of seeing some 3D printer applications developed especially for Windows. While this isn't necessarily game-changing news, it's good news. If 3D printing is going to be more than just a passing fad, it has to be something that's easy and readily accessible to normal people, rather than hobbyists and rich people. Being able to print right from your computer to your 3D printer is a good first step.