Illustration: Adam Benton

Depending on which “insider information” you choose to believe, Apple is going to release a tablet device any time between now and spring 2010. Though the online rumor mill can’t be relied on to give accurate information, the arrival of a tablet device any day now seems like a foregone conclusion. What would such a device look like? What hardware would be inside? We haven’t yet successfully planted a mole in Steve Jobs’ inner circle, but we can make a few fact-based guesses about an Apple tablet’s key specs.

The hardware in an Apple tablet--let’s call it the iTablet--would follow from the target price and anticipated software features. Let’s start there. Apple already owns the market for notebooks costing more than $1,000, but that’s a small piece of the portable computing pie. The iPhone, meanwhile, is cleaning up in the smartphone category. What Apple needs is a computing device more robust than the iPhone, but cheaper and more portable than a Macbook.

With the rising popularity of “netbook” PCs ranging from $299 to $499, the public clearly wants a cheap, lightweight computer to do a little Web surfing and email checking on the go. A $699 to $799 price point seems likely for the iTablet, possibly cheaper if bought in conjunction with a wireless data plan (from an “exclusive carrier,” naturally). As for snazzy entertainment features, expect Apple to focus on rich media, from the rumored “Cocktail” project that introduces multi-dimensional, interactive albums to iTunes, to HD-quality video and games (ever the most popular software category on the iPhone).

Keyboard stays Soft.

Don’t expect a built-in physical keyboard, but rather an improved multitouch virtual keyboard optimized for a larger screen. Web browsing? As good as the iPhone’s browser is for a smartphone, it’s still much easier to read a webpage on a bigger screen, and the iPhone doesn’t do Flash. So expect an iTablet version of Safari, which could have tabs, support Flash, and give you a lot more viewing area, so you don’t have to zoom in on and pan around pages.

iTunes on the iTablet could look and feel almost exactly like the version on your Mac. And while you wouldn’t want to write the next Great Novel on a tablet, composing an email or posting to an online forum would be a lot faster and easier with a large multitouch keyboard. E-books are a natural fit with a screen this size, as well—ever try reading one on your iPhone? Imagine swiping your finger to turn pages, dog-earing with a flick of the screen corner, and visual bookmarks that look like, well, bookmarks. You’re not going to pull out your MacBook to read Tom Sawyer on the subway, after all.

All rumors point to a 9- to 10-inch screen, which seems perfectly vreasonable. To get an idea of the size, take a Kindle and remove all those buttons and borders, instead making nearly the entire front of the device a color touchscreen. Knowing Apple, this thing has to be light and beautiful, with a minimum of physical buttons.

Illustration: Adam Benton  - Click to embiggen

Input/Output.

Don’t expect to see all the ports you find on a notebook, but we wouldn’t be shocked to find a mini-HDMI port for sending video to your high-def TV, or perhaps an SD or micro-SD card slot for removable storage, and a standard 30-pin connector for syncing, docking, and charging.

While we would love the improved quality and battery life of an OLED screen, we just don’t see it happening on the iTablet. OLED screens at this size are far too expensive. As a result, the iTablet will likely have an LCD, perhaps using LED edge lighting, with a resolution that Apple can market as “HD” (perhaps 1280x800 like the MacBook, or 1280x720 for native 720p). LED edge lighting (showing up in some new HDTVs) is like the LED-backlit screen on a MacBook Pro, only instead of an array of white LEDs behind the screen, you have rows along the edges shining toward the center of the screen, and a special film to reflect the light outward. The result is a thinner, more energy-efficient display.

Certain hardware features of the iPhone 3GS are a shoo-in for the iTablet. GPS? Check. Wi-Fi? Check. Accelerometer? Check. The digital compass will probably be there as well. While this is too large a device to take photos with, a front-facing camera for video chat is a distinct possibility. Despite the similarities to the iPhone, we don’t expect the device to make phone calls—at least, not without a VOIP application like Skype. Bluetooth is iffy for this reason. It might be included only if the radio chip Apple chooses happens to support it. Then again, since we don’t expect Apple to add a USB port (to maintain the iTablet’s thinness), Bluetooth might offer the only way to hook up to a physical keyboard.

For wireless Internet, some form of 3G connectivity is likely, especially if the device does end up being sold through an exclusive carrier with mandatory data contracts to keep the sticker price down, as the iPhone is. We wouldn’t be surprised to see a faster 3G implementation, perhaps HSPA (High-Speed Packet Access). As for the rumors of a 4G LTE (Long-Term Evolution) technology that all the carriers plan to offer someday, the track record of on-time rollouts for new cell technology is abysmal, and market penetration will be spotty for a long time. Plus, when has Apple ever been the first to jump on a new technology standard? It would be great if true, as LTE 4G technology could genuinely be called “mobile broadband.” Speeds should be 10 to 50 times faster than 3G, and latencies greatly reduced, but it’s a nascent technology, and likely to be expensive and power-draining at first.

NEXT: Modified OS X for the Win.