Microsoft is the last of the three big video-game console makers to unveil its latest gaming system. The unveiling comes nearly eight years after the Xbox 360 went on sale. It follows last fall's debut of Nintendo's Wii U and a preview in February of the upcoming PlayStation 4 from Sony.
When Nintendo first broached the idea of multiple-screen video games in 2004, many critics were skeptical that players could focus on two images at once. Yet the handheld DS, blending one touch-sensitive screen with a slightly larger video display, became a runaway hit.