The Apple tablet rumors are flying again, this time with an early 2010 landing date. I’ll admit the notion of a slender, gorgeous Jony Jobs slab of glass and aluminum is pretty tantalizing, and it got me thinking about what it would take to get such a confection out of the Cupertino kitchen.

Tablets are a tough form factor. They don’t give you the general purpose computing affordances of a notebook or desktop computer, and they are too big to be unconsciously portable like a phone. Tablets are in between, and so is their use model; this may be why an Apple tablet has been such a long time coming. Today’s Apple wouldn’t just push out a new form factor without some fundamental design principles and business directions in mind; it would be something with a tremendous level of ambition and a large, disruptive market potential. A new Apple product category would have to deliver crave-worthy ID, industry-changing functionality, and a signature user experience across hardware, software and services, along with a strong business model to sustain it. So what are the possibilities?

Let’s assume that we are talking about a product that conforms pretty closely to the rumors – that is, a thin, rectangular slab ~10 inches on the diagonal, with display across most of the surface. Let’s also assume it has similar features to the iPhone: wireless WAN, LAN & PAN, GPS, digital compass, accelerometers for orientation and tilt sensing, multitouch screen, decent integrated camera on the backside, at least 32GB of flash. At 3x the size of iPhone, it would fit ~4200mAH of Li-polymer battery, plausibly enough for a full day of usage. So far, it’s a big iPhone, and mostly a big “so what”.

At this point, I’m going to put an OLED display on my wish list. I doubt even Apple can drive the cost of a 10″ OLED down far enough by next year, but if they did it would be a flat out gorgeous screen and with lower power draw to boot. The iPhone’s display is good, but trust me, an OLED would be to die for. In a rational world we’d see it on the smaller devices first, but you know they’re working on it, so let’s cross our fingers that it comes true in 2010.

Now we need to talk about the stylus. The natural use model for a tablet is handwriting and sketching, and Apple knows it. Getting handwritten input to work flawlessly, and integrating stylus input with the Cocoa app framework are the grand challenges of the Apple tablet. Get these to fly FTW. Yes, there will be a soft keyboard for light text entry when needed, but the stylus is make-or-break in my eyes. It’s a hard design problem, but if anyone can pull it off, it’s Apple.

Okay, let’s pretend this cool little box exists. What would it be good for? How about:

* The best digital Moleskine notebook in the world, with infinite pages and web integration and lovely sketching tools (please Apple, go steal Sketchbook Pro from Autodesk, k?), and when I snap a picture or vid, I can drop it right into the pages of my notebook. As a bonus, how about continuous audio capture synchronized to my note taking, with random access playback. Kind of like the LiveScribe pen, but without all that annoying paper.

* The best map in the world, the Killer Map. Probably in partnership with Google of course (OSM in my dreams!). Including street view when you hold it up in front of you. Including wayfinding and points of interest overlaid on the image, like Layar, Wikitude et al. Including locative post-it notes scribbled in haste and left hanging in cyberspace. Including a library of fantastic historical maps, accurately  georeferenced (calling David Rumsey). Including a new geocast category in the iTunes store. C’mon Apple, there’s much to do here!

* The first full color, rich media eReader for magazines, plus downloads and subscriptions via the iTunes and/or App stores (hello disruptive new business). Natural page turning gestures, high quality images, video and fontography, embedded contextual ads with built-in analytics, handwritten annotations, social media affordances, and maybe even a new data format for digital zines to tie it all together. A bevy of high gloss launch titles – Aperture, Architectural Digest, Gourmet, Vanity Fair, National Geographic, Wired, that sort of thing.

* Games, well that’s obvious. That 10″ screen opens up a lot of possibilities, assuming they can put a decent graphics pipeline behind it. With its onboard GPS and compass, we can look forward to a lot more real-world street games. And as a bonus, now we can have games that use handwriting, like crossword puzzles from the NY Times. Hmm, what would a locative crossword puzzle look like, played in the streets of Manhattan or the wilds of the Adirondacks? You laugh, but something like that might just turn my dad into an Apple customer.

* Of course, this little tablet will be an excellent web browser, certainly far exceeding the iPhone web experience on display size alone. Dare we hope for tabbed browsing, HTML5, sensor integration and Flash support? Indeed we do hope.

* A very nice HD video player, again linked to the iTunes store. Hey, include a little easel stand and it’s a portable TV! Oh, maybe it will get Vcast if the Verizon rumors are true :-p

* The world’s nicest digital photo album, linked to…umm…probably other companies’ photo sharing sites. But nice. Psst, want to see every picture I ever took?

* And just to close with a further bit of speculative fiction, Apple could decide to make this tablet the world’s coolest platform for augmented reality and physical hyperlinking, an Internet magnifying glass. Like this.

So what do you think? Care to join in the speculation? And if it turns out that Apple really isn’t doing any of this, who do you think could, or should, or would?