When Steve Jobs unveiled the iPad I didn't like it. It was just to basic, I thought I'd never buy one unless they upgraded it quickly.Three months later I had just touched one and "got it". The UI made all the difference, it IS just a gimped laptop but with an interface that makes what you can do fun.
I just unpacked my own and tried out most of the functions I've been looking forward to. Unsurprisingly it feels like my iPhone only the screen makes the entire experience slightly more immersive.
As I'm typing this there is no doubt in my mind that this is the future of computing, at least the near future, but should you get one? If you work on the road or need to upgrade a net book the answer is Yes. If you have a great laptop or use a desktop machine however, don't. Not yet, let the platform mature a bit and you'll be much less grieved.