I think the key is the merger of personal media, communications, entertainment, and home automation. Imagine that you're reading a magazine article on the iPad. This reminds you of a band. You go over to the media remote app and put an old album of theirs on. Out of curiosity, you do a search and go over to the Amazon page and order their new song. This reminds you of something else that you ordered and you check on the package tracking. You see that it will arrive when you are out of town and message your girlfriend to see if she'll drop by and pick it up off the front steps on the way home from work in a few days.
Most of that, you could do on the PC. But with the iPad, you could do all of that just sitting on the couch.
The home automation part: You call up a recipe app as you walk to the kitchen. You flip to the ingredients view and you see that you need some more ginger. You flip the ginger into a shopping cart app for Whole Foods and it gets added to your "Personal Shopper" bag for you to pick up later.
Most of that, you could do on the PC. But with the iPad, you could do all of that just sitting on the couch.
The home automation part: You call up a recipe app as you walk to the kitchen. You flip to the ingredients view and you see that you need some more ginger. You flip the ginger into a shopping cart app for Whole Foods and it gets added to your "Personal Shopper" bag for you to pick up later.