iPad owner here...
It's an instant-on small computer which lives in the lounge. Great for:
- checking stuff on the internet
- games (lots, and many are very, very good)
- multiplayer games with the rest of the family (Marble Mixer is great fun for four)
- education (eg. helping kids with maths homework and need a graphplot: QuickGraph)
- music apps: some of the music apps use the multitouch interface in very imaginative ways
- excellent Apple TV remote app
(quick list off the top of my head)
Ok, most of this you can do with a laptop - but none of this requires a permanent, physical keyboard. And don't forget, this is about the size of a small magazine, is instant-on and has a battery life of over ten hours.
When I got ours there was an initial rush in using it, but it's settled down now to the point where it needs recharging every three / four days. It's just really, really useful.