Yes. And a public campground is one of the places I use the iPad, if there happens to be 3G or better coverage in the area. Also at rest stops, and even staying in hotels where the WiFi setup tends to be cranky, requiring you to be logged into the hotel chain's portal.
The data coverage won't be everywhere, there is a lot of dead air space out in our part of the country, but coverage is getting better as they fill the landscape with wind farms, since it seems operation and maintenance of those things requires people to have mobile data connections, so they pay for the towers.