Newton was more a PDA than a tablet, it was only sized as big as a tablet because of the technology of the time. It failed due to a lack of interest and becaue there wasn’t a demand in the market niche it filled; in comparison today all it’s features could be done on an iPhone with no problem. Although one of my iPhone gripes is that for all it’s advanced tech the iPhone still can’t fully duplicate the old Newton as a PDA. Half the programs aren’t there natively and when you “get an app for that” you can’t run multiple or background apps.

Back to the modern iTablet (not its real name, I just made that up for simplicities sake), PCWorld writes an article why they don’t think it will work. I usually don’t agree with PCWorld but here they made a few good points.

While I think a multi-touch display is a great idea, using it to host a virtual keyboard takes too much real estate on a petite 10-inch display. Eliminating the physical keyboard would make the device very thin, but at the expense of the screen protection a closed laptop offers.
The iPhone and iPod Touch work as keyboard-less devices because they are designed to be hand-held—something which would be difficult and clumsy with a 10-inch tablet.

Exactly why the onscreen keyboard on the iPhone sucks, it takes up more than half the screen in landscape; 9-10” screens are barely big enough for surfing as it is, there is no room for a keyboard. And on the tablet you can’t thumb type because of the size of the tablet. When typing you’ll need to sit the tablet down on a flat surface or in your lap which will make viewing the screen a royal PITA, especially if they stick with a glossy fingerprint smudged screen.

On the plus side there should be more room for the keyboard than on the iPhone, and people are brainwashed enough to ignore that and some even call it a “feature”. Also as a netbook/tablet the keyboard will be relegated to more infrequent use; it’s the same reason I can barely stand the keyboard on my 9” EEE PC, I never really have to use it except in a pinch. But I still think a convertible laptop/tablet like the Asus T91 is a much better way to go to get the best of both worlds in this device size.

The second major strike is the possibility of the tablet running the iPhone OS or a hybrid; at this point all we have is rumor but many people hint at an iPhone OS relation running on an ARM processor for the tablet.
The iPhone OS as-is would be an epic fail. Unlike Android and Windows Mobile the iPhone OS is built to run on one platform and one resolution only and all apps are optimized for that phone, that way Apple can be sure all apps will run well. If the iPhone OS had to deal with all the variations in hardware that Android and WM deal with it’s wouldn’t be nearly as slick. Trying to stretch that phone OS out to 10” wouldn’t work without some major redesign. Thus a hybrid OS is far more likely

The Hybrid OS that the tablet will likely get is something that looks like a big iPhone OS but has some added capabilities to it; however this will still be insufficient.

Regardless whether this is designed to compete with netbooks or not, at 10” it will be placed in competition with netbooks in everybody’s minds anyway. So running anything less than a full OS will seem crippled when compared to netbooks/tablets running Windows or Linux. Apple will have to go with OSX or an “OSX Basic”. But Apple charges the price premium to put good hardware in their devices so a thin 10” tablet running OSX is entirely possible if they can keep the battery usage down.

I disagree with PCWorld that the tablet will be a train-wreck. It will sell like a beast and the Apple faithful will ignore the keyboard drawbacks or short battery life or limited OS. Like the netbook fanatics they will load complex software into device poorly designed to handle it and claim that since it can barely run without crashing the tablet that it’s “full featured”. But best of all it will accelerate competition in making a useful tablet PCs, hopefully prodding competitors like Asus into making a convertible netbook with a decent video processor (Asus T92 perhaps?) that will combine the best of both worlds between the Apple tablet and the current netbooks.

I’ll be happy just so long as we don’t get the “iPhone effect” where people become so brainwashed they start to remove advantages like a physical keyboard, stylus input, background apps, and copy/paste in an effort to copy Apple.