Here, I got something for you: I was thinking about it earlier, and I was wondering how I'd get something to print from the iPad, being that there's no normal USB connection. And it hit me in the face: Why would I want to print? If it's something I want to give someone else, I'll send it to them through email. If it's something that I'd want to refer to later, I'd just have my iPad with me later.
The iPad kills a lot of the reason for having paper.
I print via WiFi, but if I didn't I could print via Bluetooth. I don't think its a coincidence that Apple has made Bluetooth versions of their peripherals. There are very few things that USB is required for anymore (mostly flash drives and software dongles).
Plane: e-ticket. I can't remember when last I had a paper ticket. I fly a lot.
Train: subway card; on-demand ticket dispenser at station. Even when I use the Acela I don't need to print anything.
Show: uhm, they should accept electronic display (then I'll use my iPhone - last concert was Kylie Minogue, and I got a paper ticket on the 2nd hand market)
Article: physical magazine or online reading. I never make notes on the physical article (then I'd have to have a filing system to keep it)
Paper: send it to me in PDF or some other open format; I'll send review notes back electronically.
Other reading material: books?
For some people it may be more convenient to print stuff, but not for me. Paper => physical clutter.
The Bureaucracy won't give up paper easily. Please tell me the iPad will kill (at least that part) of The Bureaucracy? Maybe a paperless society is happening closer to the center of the universe. But it isn't here.
Apple's site does list a "iPad Camera Connection Kit" in the Accessory section of the "Tech Specs" page. It allows connecting with USB cameras. So the hardware is there. Who will make the software?
The iPad kills a lot of the reason for having paper.