Microsoft plans to introduce tools to help developers build Xbox Kinect-compatible apps for Windows PCs. It's a bold move, but Redmond will need more of such innovations if the humble desktop is to remain a relevant computing platform in the age of tablets and smartphones.

Microsoft originally developed Kinect for its Xbox console, letting players interact with games through physical gestures that are picked up by sophisticated sound and motion sensors and translated into the equivalent of controller commands. Unlike the Nintendo Wii, Kinect users don't need to grasp any hardware devices during game play. The system has proved so popular that it was recently declared the fastest-selling tech gadget of all time by Guinness Records.

But Anoop Gupta, a Microsoft distinguished scientist and creator of the Kinect for Windows Software Development Kit, which ships later this spring, told me that the company thinks hands-free computing is about much more than entertainment.

"We see this not just for gaming, but for all aspects of the ways in which we interface with technology," Gupta says. Microsoft thinks the so-called natural user interface (NUI) has a role to play in healthcare, education, robotics, and many other industries, he says.

Kinect-enabled apps could allow office workers to go about their tasks more efficiently and comfortably. Opening and closing files and apps with, say, the snap of a finger instead of the click of a mouse, could, at the very least, cut down on repetitive stress and other ergonomic injuries. The Occupational Safety and Health Administration estimates that RSI costs U.S. businesses $20 billion a year in lost productivity and compensation claims—and the computer mouse is one of the biggest culprits.

Will workers one day be manipulating files with gestures instead of keystrokes? "I can definitely see it," Gupta says. He also believes Kinect would be a useful addition to telepresence videoconferencing applications and other general-purpose business tools.

Such advanced usage scenarios will require horsepower, memory, storage, and expandability beyond what's currently available in a tablet. So breakthroughs in NUIs alone could breathe new life into the PC market, which contracted 3.2% in the first quarter, according to IDC.

What's more, Kinect proves that, despite Microsoft’s tendency to produce "me too" versions of well established rival products (see Zune vs iPod, Windows Phone 7 vs iPhone, Bing vs Google), Microsoft is still capable of true innovation when it gets out of its own way. It's no coincidence that Kinect emerged from Microsoft's games division, which isn't as wedded to legacy technologies as most of the company's other units.

But more innovations will be needed if Microsoft hopes to maintain Windows PCs' centrality to business computing as tablets and phones gain functionality. Kinect is all about redefining the user interface, but that alone won't be enough to stem Windows' eroding market share. Microsoft needs to focus on taking PCs to the next level in terms of what workers actually use them for—content creation, communication, and collaboration.

Gupta agrees that Kinect is only the first stage in redefining the PC experience for workers: "This is just one major step forward in the continuous evolution that we'll see. Natural user interfaces will be important, and Microsoft is investing in those. Kinect provides an initial glimpse."

Will there be direct support for Kinect in Windows 8? Gupta wouldn't say. If there is, Microsoft and its partners will move a lot more PCs than expected next year.