The iPad is a extension of a computer, there really isn't any "must have" feature that isn't already on laptops.
The iPad needs a stand to hold it, the keyboard on it is lousy to type on, the screen is glossy and reflects everything, the storage is poor, the dual core Atom like processor is weak, it can't run Flash sites, you can't use software other than what Apple approves of and worst off you have to hold it to see the screen.
Instead of a iPad for very light portable uses, I got a 160GB netbook for $220 that I installed Linux - Like XP on, comes with tons of free software and I can use Flash too. 😀
Cheap, portable, more storage and if I lose it or it gets stolen, it's only $220. 😉
Not a highly sought after iPad that I got to worrry all the time about.

The iPad has it's uses, but $500 is a lot for no storage and being chained to the AppStore.
I have a nice i7 Quad core with a 1GB Radeon 6750M video card on a 2.2 Ghz 15" MacBook Pro or better is a clearly superior alternative and a much better value for your money, despite having to put up more up front for it.
You can 3D game, you can run many operating systems, run Windows games, Linux etc.

That's three operating systems running at once, Windows 7 64 bit, Linux Mint 11.04 64 bit, iTunes and a wild Hyperspace screensaver running as a desktop background.
I blow Mac users as well as PC users away with my machine, the raw power is awesome. 😀
Even playing a 3D game in Windows, in a virtual machine under OS X. 😉

Problem with the iPad is one has to continously buy more stuff to get some functionality out of it.