Apple has approached them as big handsets whereas Microsoft is treating them as somewhat smaller touchscreen PCs. Microsoft will challenge Apple's assertion that bold touch interfaces are not the province of the PC. But while Apple decided to break with tradition on the iPad's platform, Microsoft could not escape its personal computing legacy. To leave the existing base of Windows apps behind would be tantamount to shooting the OS in the head.
This isn't to say that Microsoft didn't have alternatives. One might have been to have different Windows "personalities" depending on the form factor -- a traditional windowed interface for desktops and laptops, a Metro-like UI for tablets, and a Media Center UI for home theater PCs. In fact, with the blurring and adaptability of form factors these could all easily exist in a "schizophrenic" convertible tablet that might look something like the Eee Pad Transformer. It would present a traditional Windows interface with the keyboard attached, the Metro-like UI with the keyboard detached and a Media Center UI when connected to a TV via HDMI or presenting video witlessly.
It's going to be an ugly transition to Windows 8, and not just figuratively.
Such a scenario might provide better user interface consistency, but it would ask a lot of developers. What Microsoft is now calling Windows 8 is no mere skin. The company is enabling app developers to take on a similar appearance and UI conventions to that of the new "desktop." This means that, in the short term, at least, most developers will need to choose between a mouse-centric and touch-centric approach. And because of this, for the foreseeable future, Windows 8 could present a fractured user experience (although of course it will be up to the user to decide whether to use, say, an app with a desktop UI for their tablet PC.). It's going to be an ugly transition, and not just figuratively.
Over the course of Windows 8's run, though, Microsoft will have challenged developers of all kinds to meld the full power and depth of a PC app with the simplicity and discoverability of a finger-friendly tablet UI. The Windows team has laid down the gauntlet at the feet of the Office team, for example -- a contrast to 2007, when the release of Windows Vista arrived in lockstep with a new version of Microsoft's popular productivity suite.
How will Office, Photoshop, AutoCAD, and other advanced applications adapt? Will it be possible to have any kind of common UI between an optimized Windows 8 experience and Macs? If Microsoft can bring Windows developers along as it shifts the fundamental principles of Windows' UI in Windows 8, the new windows the operating system opens may provide a glimpse of a future user interface.
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.