First off, I haven't seen an iPad, or even a picture of it. I haven't read any specs on it. Everything I think I know about the iPad is, at best, second-hand, from stuff I've heard on the radio or read on-line. So, I freely admit I'm talking out my ass.
Strike that. I'm looking at the specs now at Apple's site.
CPU: 1 GHz custom chip
RAM: doesn't say
HD: 16, 32 or 64 GB flash drive
ports: dock connector, headphone jack, micro-SIM card tray (for the wifi & 3G models)
wirelessness: wifi, bluetooth & 3G
display size: 1024x768 pixels (the same size display as the 1990's-era Pismo PowerBook)
controls: on/off/sleep/wake, screen rotation lock, volume up/down, home
inpute: fingers, keyboard (one of the docks Apple sells had a built-in keyboard) and I'm fairly confident that if it's got bluetooth, you can use a bluetooth keyboard.
price: starts at $499.00
However. From what I've heard, the iPad, like the iPhone, will only run Apple-sanctioned apps. It runs on the same OS as the iPhone, and it will only run one app at a time.
Last year, I decided I wanted an e-book reader, and wasn't going to stick myself with a nearly useless kindle or sony reader. Instead, I bought a used Fujitsu Stylistic tablet PC, an ST5010. Let's look at those specs:
CPU: 1.1 GHz Pentium M
RAM: came with 1 GB, upgraded to 2GB
HD: came with 60 GB HD, upgraded to 160 BB HD
ports: modem, ethernet, VGA video-out, FireWire, microphone, headphones, 2xUSB, multi-function SD card slot & PCMCIA slot
wirelessness: wifi, added teeny-tiny bluetooth dongle
display size: 1024x768
controls: e-mail, screen-rotate, exc, enter, Fn, security, page up/down and line up/down buttons
inputs: stylus, any usb, wireless or bluetooth keyboard & mouse, just like any other computer
price: $300 or so, on eBay. Add in the additional RAM, bigger HD and bluetooth dongle, and I'm looking at somewhere between $450 and $500.
So, I've paid, roughly, the same for my ST5010 as for an entry-level iPad. In raw speed, it's a touch faster than the iPad (1.1 GHz vs 1 GHz), but I'm sure the custom A4 chip is capable of more than the Pentium M. My HD is bigger than that of the iPad, but the iPad's flash drive is faster. The iPad allegedly gets 9 - 10 hours battery time, which beats my 2 1/2 - 3 hours, hands down.
So far, it looks like the iPad is a better value at the same price, more or less. However, there's more.
One of the first things I did with the ST5010 was to install Ubuntu Linux version 9.04, Jaunty Jackalope. This is where my tablet beats the iPad. I have a full-function computer in not much more space than the iPad. It lets me read my e-books just about anywhere, which is what I wanted when I bought it, and it lets me do anything else a computer can do, since it is a real computer, not an over-sized iPhone.