The things that make the iPad so revolutionary are the things that have been left out.
This is the computer our parents have been waiting for.
Well put. Of course there will always be people who think all that was taken out should be in there after all but I am sure there will be a myriad of would-be iPad killer options for them. Not that I think any one of those options will be one tenth as successful, in sales and usability, as the iPad.
Yes, parents and every non-technical person with a passing interest for the internet would be much better off with an iPad instead of a computer. Like the iPhone it requires relatively no maintenance to operate, no dedicated space, no kid to come and set it up, instal hardware, etc. All the usability of an iPhone on a big screen.
Looking towards the future, it is feasible that most homes will have some kind of media server, like a Time-Capsule, Apple TV and Mac Mini rolled into one, and iPads to access the content on it. To take that idea one step further, if there are no more CDs and DVDs to consider (for ripping music and movies), you could even get by without a home server and just store all your content on a service like Me.com (or 'the cloud' to use a popular term). Of course much faster internet connections for everyone will have to exist for this to be possible but my point is that iPads are more likely to be part of the future computing experience than desktops and laptops.