And Since We Still Don’t Allow iPhone Tethering, We Can Guarantee That Wi-Fi-Only iPads Won’t Overload Our 3G Network

Here’s the real reason AT&T was able to offer such a breakthrough price on data plans for Apple’s iPad in the U.S.: The carrier doesn’t expect many people to buy them.

Though $14.99 per month for 250MB of data and $30 per month for unlimited data are bargains, particularly considering that 3G service for laptops costs an average of $60 a month, AT&T (T) doesn’t see many people taking advantage of them.

During an appearance at the Morgan Stanley (MS) conference in San Francisco Tuesday, AT&T CEO Randall Stephenson said he doesn’t expect Apple’s (AAPL) iPad to generate a lot of new 3G service subscriptions for the carrier.

“It will be interesting to see customer reaction to the iPad,” Stephenson said. “My expectation is that there’s not going to be a lot of people out there looking for another subscription. We think it’s going to be a largely WiFi-driven product.”

That seems like an odd remark from the CEO of a company that’s got the exclusive on iPad 3G connectivity in the U.S. Honest, though. The consensus among analysts seems to be that most folks in the market for an iPad will buy the Wi-Fi-only version. At $499-$699, the iPad is a real head-turner and relatively easy on the wallet. But at $629-$829, it becomes more of a “Do I really need this thing?” question.

One last point worth noting here: Asked about the fate of the company’s iPhone-exclusivity deal with Apple, Stephenson said he expects the iPhone to be a staple of AT&T’s business for “quite some time.”