Both Apple and Microsoft are driving toward unified operating environments across smartphone, tablet, and personal computing platforms. In some ways, Microsoft is ahead of the curve. Windows 8, Windows RT, and Windows Phone 8 will offer nearly identical user experiences. With the release of iOS 6 and Mac OS X Mountain Lion, Apple is taking another step along the road to user-experience integration.

Not all users are on board with unified environments, though. . Running the Metro interface on a desktop system, or even a laptop PC, seemed to be a baffling decision on Microsoft's part, until the announcement of the Surface. Windows 8 and the Surface are closely intertwined, and it’s clearly the direction Microsoft wants to take the operating system--and its users.

Apple’s huge success with the iPad, iPhone, and MacBook Air has prodded traditional PC manufacturers to explore new designs. Although Apple hasn’t significantly eroded Windows’ market share on the desktop, Apple’s laptop sales have gained ground. The current generation of iMacs has established the standard for all-in-one systems, while the MacBook Air is the poster child for ultrathin, mobile computers. The popularity of the Air likely spawned Ultrabooks--the skinny, lightweight laptops that Intel is currently pushing PC manufacturers to build. Over the next month or two, Intel anticipates a wave of Ultrabook releases, with dozens of new models flooding the market.

The new MacBook Pro with Retina display brings 2880-by-1800-pixel resolution--which translates to a pixel density of 220 pixels per inch--to Apple's premium laptop line. PC manufacturers aren’t as far behind as they seem to be, though: The new crop of 13-inch Ultrabooks with 1080p displays offer 160 ppi. It’s clear that the bar has been set.