I predict the iSlate will have a simple, intuitive user interface with multitouch gestures. In contrast, Windows tablets have so far been designed like conventional laptops, with pen input grafted onto a conventional Windows interface.

Reason 2: Apple's online stores

Part of the success of iPod and iPhone was their seamless linkage to Apple's iTunes and App stores. Paying for and downloading content or software is a no-brainer. Apple will extend this online family to include new kinds of iSlate apps and content. The Android Market is growing, but it is still far behind Apple's stores in integration, scope, and sophistication. And where, exactly, is the Windows equivalent of the iTunes/App store? Exactly my point.

Reason 3: Superior ergonomics and user experience

The iSlate should deliver a user experience noticeably superior to anything else available in this market. This is Apple's raison d'etre. They won't blow it. I expect sharper text than we've seen on any touchscreen or color display (including the best e-book readers). The display will be impressively bright, with a very wide viewing angle in both the horizontal and vertical directions, and should offer new multitouch gestures not available on current iPhones and iMacs/MacBooks (but undoubtedly planned for future models). All this will live in a beautiful case that seems slimmer and lighter than it has any right to be.

Reason 4: Content and apps are king

Sure, people use computers to chat and take notes. But in the YouTube era, it's much more about swift and continuous access to content of all kinds—not just music. The iSlate's operating system will have a close family relation to the iPhone's, both because it's well suited to touchscreen, mobile apps, and because it will let Apple leverage its huge collection of apps. Developers will be able to easily port their iPhone apps to iSlate's larger format and take advantage of its new features. Developers will leap at the chance to sell apps into two markets, instead of just one.

There will be subscription tie-ins to beleaguered blue-chip print outlets, such as the New York Times and, say, Time magazine. Of course, there will be e-books for iSlate's built-in reader. And, likely, there will be content from movie studios, and TV and sports networks. Some, maybe all, of this content will be delivered by new types of apps that go beyond the Web experience to take full advantage of the iSlate's rich, unique feature set. Steve Jobs would never settle for less.

Reason 5: Multiplicity of connectivity

I expect Apple to have learned something from its iPhone/AT&T experience, which was a success but obviously has problems. Exclusivity is a two-edged sword and I'd be surprised to see Apple get in bed again with just one wireless provider, even one with fewer 3G capacity issues than AT&T (e.g. Verizon). The iSlate should have 3G from a choice of providers, who will help lower the iSlate's presumably steep upfront purchase price in exchange for multi-year subscriptions. That model has worked for years to make pricey products accessible to many consumers. Of course, there will be the obligatory Wi-Fi and Bluetooth, but 3G is essential: The iSlate couldn't serve its intended purpose if you had to hunt down a hot spot every time you wanted to access the Net.

The time draws near

As I write this, we're slightly more than 24 hours from finding out how many of these expectations will be fulfilled—and what other rabbits Steve has stuffed into that bottomless hat of his. This will be a fascinating time for gadget lovers and anyone who likes to take advantage of the latest technology.My colleague Donna Tapellini and I will be in that San Francisco theater when whatever is to be revealed is revealed. Check back here on this blog for news and expert analysis from us, and all the experts at Consumer Reports. I will also be covering the goings on moment to moment on Twitter: @JeffreyFox

—Jeff Fox