I ordered my iPad and the Keyboard dock. But I wonder, should I have ordered the 10W USB Power to be able to use the keyboard dock? I want to be able to use the keyboard to type when I am away from my computer.
I can't say for certain but when I used to run a foldable keyboard off my tiny PDA, it was perfectly happy to run it without plugging it in.
I think the plugging in bit is just to allow you to charge up your iPad while using it with the keyboard (presumably because the keyboard uses the 30-pin connector and so you can't use that for charging while using the keyboard), I doubt it's a necessity. I would expect the iPad is perfectly capable of powering the keyboard off its own batteries.
Additionally, even if it did need the 10W adapter, you didn't need to order one. All iPads come with the 10W power adapter as per Apple's website:
In the box
* Dock Connector to USB Cable
* 10W USB Power Adapter
So there you go. I wouldn't really worry about it. I imagine many people will be using the power adapter with the keyboard so they can charge their iPads while using the keyboard, it likely isn't necessary.
No. The modern iPods (and all iPhones) only accept a 5V power input. Anything else will read as an unsupported accessory. Kind of strange that Apple spent time getting rid of 12V power support for their iPods and never supported it for the iPhone and now they are going back to a higher voltage. I think it would have been easier to just keep support for 12V charging (along with supporting 5V charging) and carry that over to the iPad. It would have opened up the iPad to iPod accessories from 2003 so that people wouldn't have to throw them away (as I did).