Here's an interesting rumor I hadn't considered yet: sources inside AT&T are telling Boy Genius Report that AT&T's retail stores are planning to carry the 3G versions of the iPad. It's not unexplainable, given that AT&T is the partner for the 3G service, and so I guess they have a vested interest in selling the devices. Still, when you think of "tablet computer designed for consumption of media and minor household tasks," you don't really think of AT&T. In fact, without a phone on it at all, it's just strange to think that the iPad would have a place in AT&T stores anywhere.
But if the 3G versions will make money for the phone company (and we'll bet they will), they might as well sell them. If the rumor is true, and the AT&T store is closer to you than the Apple store, you might as well check there on release day (remembering that 3G iPads will be released after their WiFi-only cousins). In the meantime, let's all hope their 3G network holds up under the increased strain.