I was just on the phone with att today and they said they are extenting the 3g unlimited plan to people who want it and were unable to get it due to ipad shortage. If it doesnt let you sign up for it in the ipad, give them a call on the phone while you still can get it.
Yes the iPad is a sinch to get used to. Its probably the only device that can do many things that a real computer can do yet any age rang both todlers, the elderly, and non technical people can use it without any problems.
Most people that dont like using computer, think they will somehow end up doing something wrong or breaking it. You cant do that with the iPad unless you actualy do slam it on the ground and phisicaly break it. No worry about deleting files and messing things up. Just do what you want to do, check email, browse the web, look at photo's.