It's a whole computer, I think, not just an iPod Touch. I think Apple sees the future of computing as ridiculously simple devices that act as a bridge between the user and the Internet/content. Really simple, easy to use things that don't crash, start up in seconds, and pretty much can be chucked anyway - even in the toilet. In simpler terms: computers your grandmother would be able to use.
I think people like Garrick, for instance, would agree to this - he's already using his iPod Touch as a secondary computing device. The iPad does what Garricks uses his iPod to do way, way better.
It's actually kinda scary, for people like me, since I'm studying computing and all that. If the iPad represents the future of computing, then by extension that would mean the laptops and desktops that we know and love today would become the archaic mainframe-equivalents of tomorrow - used only by experts, geeks and developers.
In a sentence tho, I think the iPad is basically the computer as an appliance. And I find that cool and scary at the exact same time.