What a WIMP!
Now it's time for a more philosophical discussion. A discussion that centres on this concept of the 'post-PC world'. After using the iPad so extensively, I've gotten quite worried about this whole post-PC thing, for the simple reason that for the poster child of the post-PC era, the iPad is remarkably like a PC. In fact, the device's operating system and interface are remarkably conservative.
This worries me because as it stands right now, the iPad is being held up by the technology world as the end-all-be-all of tablets, the one tablet everybody else should aspire to. The iPad is now regarded as the golden standard, and my fear is that other manufacturers will be too scared to try and take the tablet - specifically, the interface - beyond what is currently available on the iPad, killing innovation and experimentation right dead.
And that's a problem. My hope was that with the surge in smartphone sales, with various new players vying for market share, and now the nascent tablet market, we would see a wide open field with lots of experimentation and attempts to move the computer interface beyond that of the WIMPed desktop metaphor of the 1970s, which has dominated all GUI development since.
And yes, which dominates on the iPad too. While the device as a whole may very well be revolutionary (and I think you can make a solid case that this is, in fact, so, but I'll get to that later), the interface decidedly is not. In fact, line this up next to any desktop interface, and you'd be hard-pressed to find the differences. It's got windows, icons, menus, and a pointing device (your finger), and is based around the concept of the desktop (Springboard).
The thing is though - the WIMP desktop metaphor just doesn't translate very well to a tablet. Many people ridiculed Microsoft for trying to shoehorn a traditional interface onto tablet PCs and PDAs/smartphones with Windows XP Tablet Edition and Windows Mobile CE Pocket PC Ultimate Edition r2, but that is essentially also what Apple has done with the iPad. And it shows: the iPad's interface is not well-suited for tablet computing.
The biggest problem is that widget layout has been taken straight from the PC world, without ever adapting it for the tablet: most applications have their most-often used controls at the top of the screen. This makes no sense on a tablet, which you'll generally be holding with your hands on the lower half of the device. The end result is that you'll be frantically moving your entire hand and arm up and down the device to do even the most basic of things.
This is not a problem on the small screen of the iPhone, which most people can cover with their thumbs alone. It's also not a problem on PCs, since mouse acceleration ensures there's very little mouse movement required to move the pointer to the top of the display. On the iPad, however, where every movement is a physical one involving your entire arm, this just doesn't work very well. Apple made fun of integrating touch into laptops and regular monitors because it would be uncomfortable to raise your arms to use those screens - yet, the iPad requires the exact same kind of arm-raising.
Want to type in an url in Safari? Raise your hand to tap the address field. Want to Google something? Same thing. Want to go back or forward? Arms be a'raisin'. Want to move to the next unread email? Stretch those bad boys. Want to reply to an email? You guessed it.
After only the first few minutes of using my iPad, I came to the conclusion that it would've made much more sense to position the most-often used buttons under the thumbs, at the lower half of the screen, much like how the buttons are arranged on handheld gaming devices. See the below illustration.
The end result is that there really isn't a truly comfortable way to hold and use the iPad; no matter how you sit, stand on your head, or walk around - it's never truly comfortable. You can lie it down in front of you on a desk using the Smart Cover, but that is hell on your neck (you have to look down all the time) and you'll have to keep your hands raised at all times since you can't rest them on the screen. Worse yet, you'll still have to raise your hands all the time to use the controls on the screen. You can set it upright with the Smart Cover to resemble a laptop screen - but then we're back at square one, with the additional annoyance that you can't type this way.
The sad thing is that the instant success of the iPad seems to have killed innovation in the user interface aspect of tablets right dead. Android adds its widgets into the mix, and webOS does some cool stuff with cards, but essentially, they are one and the same - warts and all. I'm genuinely afraid that due to the success of the iPad as it currently exists, Apple will be reluctant to innovate in the UI department, while others will just be content with not deviating too much from Apple - they are the ones to beat, after all. This market is potentially huge - nobody will take the gamble with an innovative interface. New and fresh ideas will be discarded because 'it's too different from the norm (i.e., the iPad)'.
The same happened in the PC world. Since Xerox, 40 years of UI stagnation. Sure, things got prettier (and more resource-intensive), but the concepts underlying the Alto and similar early UIs have changed little - and the iPad follows these set UI conventions diligently. This is not a post-WIMP user interface. Enlarging buttons and using a finger does not a new paradigm make.