The iPad is a great tool for consuming information, but not so good at communications or creation. A month in, I've never heard of anyone doing serious work on an iPad despite Apple's efforts to shoehorn a full office suite into the thing.
However, people love it despite the limitations. The iPad's a device that's just plain fun, and that counts for a whole heck of a lot. Apple will probably sell millions of them, and it looks like they have a good shot at creating an enduring category.