As easy as we think it is, some old people...are just hopeless
Maybe we only think it's easy because we learned how to do this stuff when we are young and our brains were still developing.
When you think about it, there's nothing especially intuitive about sliding a plastic mouse around on a pad, and learning to relate this to how a tiny pointer is moving around on a screen in a totally different plane. We all LOVED this when we first tried in a Mac, because it was so much easier and faster than typing commands on an empty screen. But it's still a learned technique and doesn't come naturally or effortlessly.
I think the iPad is different. You really can point and touch something (even if the "thing" is just a graphical block or something on a screen) and you will get immediate feedback from how the device responds. And you won't need extremely fine vision or precise hand-eye coordination because everything will be bigger.
I'm not saying that the iPad is JUST for old people. (Or for children, who should also take to it like crazy.) As Moocher points out above, the fact that it's easy to use doesn't mean it's a "simple" device. I expect that many of us will find it pleasurable to use because it removes a layer of abstraction between ourselves and what we are asking the device to do for us.
I agree with Wolfpackfan, though: this "old people are hopeless" comment is condescending, and also rather heartless. These folks can deal with demanding, non-user-friendly technology like manual typewriters, sewing machines, old-fashioned steam irons, and internal combustion engines that you had to crawl under the hood and tweak now and then to make the car start. Give them a little respect, please.