Practically every statement you made needs correcting so I will just quote all your errors in one place, then correct them below:
...the real reason the iPad succeeds where other laptops fail is that it's the first tablet that didn't suck. Every tablet before it has had a resistive touchscreen and a swivel-hinge keyboard, with the CPU under the keyboard. The iPad has the CPU with the display, and no keyboard. If you want a keyboard, you buy an external one.
Every tablet before the iPad had a hard drive. Hard drives are big, and draw a lot of power. That is, they suck.
Every tablet before the iPad had an Intel CPU. Intel CPUs are big, and draw a lot of power. That is, they suck.
Every tablet before the iPad ran Windows. Windows is designed for PCs. For tablets, it sucks.
Every tablet before the iPad weighed in at over three pounds, because of the Intel CPU, the hard drive, the hinge, and the battery required to support all that. You couldn't hold them in your hands unsupported for ten minutes, much less an hour--you'd have to cradle them. They were designed to do too many things, so they sucked at the one thing tablets really need to do--replace a pad of paper or a book.
Every tablet before the iPad had a battery life of maybe five or six hours, if you were really careful, and two or three, if you weren't. The iPad's battery will last through a full work day of full time use. It doesn't suck.
That's why it's the first tablet to succeed in the market.
Your assertion of suckiness is based on the remainder of your statements which are flawed, my corrections will continuously refute your claim.
Actually, slate form factors (i.e. no keyboard) were around in 2001. I've been using slate style tablet PCs for over 5 years.
I could have bought a tablet PC that didn't require a pen, but that system didn't make for good handwriting. The iPad doesn't either.
You are almost right about the hard drive, flash hard drives weren't available in 2001, but they started to be used over a year before the iPad came out - they were a horendously expensive option at the time so I decided against it.
Every tablet PC had an IBM compatible (that includes AMD) CPU and they still do - it allows them to use any software written for Windows. Some use the new Atom processor, but I prefer a powerful processor and the new i5 seems to be a sweetspot.
Most tablets ran the Tablet edition or Vista and now Windows 7 - all of which were designed to be used by pen and with Windows 7, multi-touch too.
Slate form factor tablet PCs often weigh less than 1.5kg - my current one does, and so did the one before it - and they had A4 size screens! I have carried my tablets around, using them for hours and I am no muscle man.
I often tout the benefit of a tablet PC over paper, it's just as easy, has undo, allows me to move text I have written really simply. I can copy diagrams as easily as my lecturers could draw them. My work is backed up as soon as I arive home as One Note syncs with all my other PCs in the house. I can print and markup, take a picture and markup or even copy text and mark it up with my handwriting, on the page, in real time as the lecturer progresses through his lecture without breaking a sweat. I have over 3000 books on my tablet PC and read from the tablet every day.
My current tablet PC with a stock standard battery got me through an 8 hour tutorial on the first day. When that battery got old I replaced it with a larger one that gets me through 10 hours.
The iPad is not a tablet PC as it does not make minimum specification as defined by Microsoft who released the tablet PC in 2001. If you want to pin a claim to fame on the iPad, it is the best Apple Newton ever created, and Apple Newtons were first released in 1991
The iPad succeeds because it is NOT used in the workplace much. Battery life is irrelevent if you can't do what needs to be done, do it too slowly or haven't the screen realestate to capitalise on the portability. There are some workplaces where the iPad will work, but not in any place I have worked.
If you had done a little research or spoken from real experience you could have saved me writing this correction. Please think of others before you post.