The successor to Windows 7 debuted today at the D9 conference, and so far it appears to be Windows Phone 7's interface and tile-style of app management bolted on top of Windows 7.

Code-named "Windows 8" by Microsoft, the next-generation operating system is notable for two features: it's the first major attempt by the operating system giants to elevate a mobile OS to desktop status, and it's expected to be touch-friendly and work seamlessly on tablets, desktops, and laptops.

Like Windows Phone, Windows 8 on tablets (and every other platform for that matter) has a screen of &34'Live Tiles&34' that provide rich data and launch deeper apps. Users can slide the tiles around on the screen.

This Windows 8 preview video from Jensen Harris, director of program management for Windows, certainly looks impressive. The "app tiles" concept from Windows Phone 7 has been blown up, expanded to suit a larger, horizontal screen. In many ways, this makes sense. Having a persistent, real-time weather or traffic feature on your desktop is something that you can now achieve with a multitude of programs and widgets, but making them look and feel like mobile apps better positions Windows to reach younger consumers whose first computing experience is likely to be a high-powered tablet or phone, not a 186 running DOS.

Windows 8 also appears to meld Windows 7's file-sharing tools to the friendlier, touch-tacular mobile interface. You can easily tap locally stored and networked photos to select them, adding them to your albums, the implication being that this would work for documents, videos, and music. Perhaps the world is, in fact, ready for a dual-input computer, one that you can use a keyboard and mouse with as naturally as you can tap, swipe, and pinch its screen. This is definitely one aspect of Windows 8 that must be watched.

Most importantly for legacy Windows users, including all of us on Windows 7, getting to the Windows 7-based view is simple. All you'll have to do is swipe up from the bottom of the screen, although it's not really clear how well this would work with a mouse. Windows 7 programs are expected to work on this new version, said Steven Sinofsky, president of Windows, although this doesn't jibe with what we heard at Mix 2011 about Internet Explorer 10. The next version of IE, at least as of April, was not expected to work on pre-Windows 8 computers. What's more logical to conclude, although not guaranteed, of course, is that the Windows 8-specific features of Internet Explorer 10 won't function in Windows 7 or older, although the more traditional aspects of the browser will.

Another important nod to current users is that legacy Windows 7 hardware is expected to support Windows 8--again, at least so far. It's certainly not out of the realm of possibility that Microsoft could pull an Apple here and force people who want to upgrade to buy newer hardware.

So, we've got probable legacy hardware support, potentially easy access to the traditional interface, what appears to be some smart sharing features, and a nifty split keyboard for mobile usability. We also know that there are questions surrounding programs, how many major core Windows legacy programs will be supported, and how the traditional Windows 7 programs that do work on Windows 8 will function under the greasy touch of a finger when they currently require the precise control of a mouse.

Screenshot of Windows 8

That leaves us with the two biggest questions, ones that will only get answered once consumers get their hands on whatever Windows 8 winds up getting called. The first is, do people really want a dual-operating system setup BlueStacks seems to think so, offering an intriguing marriage of Windows 7 and Android, but that hasn't hit the public yet. Although Microsoft says that the integration between the HTML5 and JavaScript-powered Windows Phone 7 side and the traditional Windows 7 side is tighter than many would expect, that doesn't mean that a double-dose of Windows is the upgrade people want.

Riding the tail of that question, we're also left wondering whether Windows Phone 7 has had the kind of consumer impact that warrants this elevation. According to Neilsen market research, Windows Phone 7 commands only 1 percent of the U.S. smartphone marketshare, and as CNET's Donald Bell noted during CNET's Live Blog of the Windows 8 reveal at D9 (read the transcript here), the WP7 interface is the successor to the discontinued ZuneHD.

There's too many reasons that this isn't "Vista II: Electric Boogaloo." Windows 7, and this successor, are both Microsoft's first hardware-downgrade compatible operating systems in more than a decade. That means that the new operating system will run on less than cutting-edge hardware. Windows 7 is also a proven, successful base to bolt a more touch-friendly interface to, a critically acclaimed one that users have demonstrated they want by the still-increasing Windows 7 adoption rates in the marketplace, more than a year and a half after its release.

Were Apple to do this--bolting the popular and intuitive iOS on top of OS X with a smooth way to transition between the two--there would be far fewer uncertainties. Still, hedging bets on a look and feel that has not set the world on fire is a gutsy move, and congratulations are due to Microsoft for being the first to attempt it.