The USB thing is funny to me.
This thing is honestly much closer to a Macbook than an iPod. Who really expects a computer's USB port to be able to charge a laptop?
Bear in mind that many of the ports that people say "can't" charge it actually are charging, but only when the device is asleep. It can power or charge, but not both at once.
And, of course, some ports can do both at once and some can't do either. So it's a wide range of options which is confusing and confused people complain.
So it's a shame it had to be complicated. People would actually complain less if it just didn't charge in ANY USB ports because then at least they'd know how it worked. It really is the confusion that's the problem, I think.
But I think complaining if your computer won't charge the iPad is a bit silly. It's not Apple's fault that the USB specs don't require that level of power on every port.