The new user. Lion represents the biggest user interface change to the company's desktop experience since the debut of Mac OS X. With the Mac hard drive hidden by default, full-screen apps that hide the menu bar, and omnipresent scroll arrows put out to pasture, it even dispenses with some user interface conventions that have been around since the original Mac. The focus on multitouch gestures -- while enabling more fluidity in the user interface -- are not as self-evident. Overall, though, the gradual shift away from contrivances such as windows, menus, and cluttered icons should make things less intimidating for new users.
The iPad user. One can only wonder what features the successor to Snow Leopard might have sported had Apple not launched the iPad. The most prominent design theme in Lion has been bringing user experience elements of Apple's tablet to the Mac. This is highlighted best by Launchpad, the iPad-like collection of sliding home screens, and full-screen apps, but also includes support for full-screen apps and bundling of the Mac app store introduced with Snow Leopard.
As on iOS devices, Launchpad helps with the discovery of apps, and Apple has made Launchpad a snap (or really a swipe) to bring to the fore. However, it has somewhat of a disconnected feel from the rest of the OS. For example, Launchpad includes all the apps on your system, but changes to folders in the Finder aren't reflected in Launchpad, and vice versa. On the other hand, apps deleted from Launchpad are deleted from the Mac. (Perhaps it's no accident that the Launchpad grid is a "Matrix" in which an app getting killed in that world kills it in the actual one.")
In part because certain apps such as web browsers have had full-screen modes for some time, system-level support for this kind of presentation blends in better with the Mac user interface. Bringing your cursor to the top of the screen shows the menu bar just as bringing it to the bottom of a screen can reveal a hidden Dock. But here too, Lion is showing some growing pains as what was previously the slick Exposé user interface has been stretched to accommodate the new window or screen types via Mission Control. While Apple has abandoned the more orderly grid of Snow Leopard's Exposé implementation, it now allows one to more closely preview windows by apps (but still doesn't treat browser tabs as documents unlike Windows' Aero Peek).
Mac veterans. Prior releases of Mac OS have brought features such productivity enhancers as Spotlight, the Sidebar, Time Machine, Dashboard and Automator. While Lion has a large number of new features, they are thematically different than those of the past.
Yes, there are a few features that have at least as much appeal to those who may recognize that Lion's new default button shapes -- part of its overall more refined look -- are more like the rounded rectangles of classic Mac OS than the gelcaps of the Aqua era. AirDrop adroitly tackles a too-long unaddressed issues in terms of getting a file from Mac A to Mac B simply, securely and wirelessly, but it will have more impact when it is supported by iPhones and iPads that lack flash drive-supporting USB ports. And few of the mouse-callused would shed a tear at the need to stop saving in order to prevent data loss that autosaving should address or fail to appreciate the Versions user interface that elegantly extends the Time Machine metaphor.
If Snow Leopard represented a technical resetting, Lion represents a user experience resetting. Apple seems to be grappling with where to find the right crossovers between the OS X and iOS and the value that that merging might provide. When Switched On first discussed Lion last November, that column noted that the key was making iPad features work in the right context. While those new to the Mac fold may appreciate them more than those adjusting from longtime use of the platform, there's some work cut out for future big cats that prowl Apple hardware.
Ross Rubin (@rossrubin) is executive director of industry analysis for consumer technology at market research and analysis firm The NPD Group. Views expressed in Switched On are his own.