Ugh.
And I'd think that if it WAS a feature they'd be bragging about it. So I'm thinking it's not possible either.
I mean, I can probably find free McDonalds Wifi somewhere if I'm on the road, but still, that's really something they should work on. The entire REASON I'd probably buy 3G data is because I showed up at some flea-bag motel in the middle of nowhere and discovered they don't have internet (or want to charge $10 or something).
EDIT:
Is it written down somewhere? I'm looking for proof. Was it in the introduction keynote?
No, I'm almost positive (read 99%) you can use the existing 3G network in your remote area to activate your new 3G account. No wi-fi connection needed.
For those asking about the "phone number", the 10-digit number is properly referred to as the MSIN. So your iPad with sim-card will always talk to the GSM network (unless it is disabled; wonder how that works for battery life). You won't be able to complete the connection and transfer data unless your MSIN or IMSI is activate. But I'm pretty sure it can connect to 911 right out of the box. But it won't do GPS on a deactivated account.