I bought the 3G version of the iPad for a simple reason: Insurance.
It comes down to the fact that the way we use the iPad could be radically different in six months than how we use it that first week. I don't know what developers are going to do with it, what kind of device they're eventually going to mold it into, when it'll be socially acceptable to toss it in my satchel and carry it to brunch, or when maybe—just maybe—I might actually be able to use it to do real work instead of laptop. I don't know. But here's the thing: You can change the software. That's the whole point, even. You can't change the hardware. There is no upgrade.