I don't think the iPad OS for everyone. If you are happy with your laptop/smartphone/desktop combo for your computing needs, and never wished for something that was a little more portable than your laptop but had a bigger screen than your smartphone, well then, the iPad isn't for you, and there's nothing wrong with that.
Me, I've been waiting for the iPad for a long time. Probably as far back as when I got my first computer, even though back then, I didn't know the iPad was what I was waiting for. I just knew that laptops got too heavy if I held them in my lap for too long, and the keyboard got in the way when all I wanted to do was just read. PDAs were a good start, but they were too small and each screen could only hold a few lines of text at a time. When I got my first iPod touch, I thought we were finally getting closer, now if only the screen was bigger!
Yes, I still drag out my laptop if I need to type something long. But the iPad is good enough to get a bit of work done while on the bus or train. In fact, I'm typing this post right now on my iPad on a bus. I don't travel, but I do ride often on bus/train, and iPad is perfect for getting some work done in that situation, whereas a laptop is too bulky and awkward to use in train or bus. I've seen people typing on laptop on trains, but not on buses. I think iPad is better, even on trains.
When I left the house today, I left my laptop and walked out with the iPad, knowing I could get the work I needed to get done today on my iPad. Instead of carrying a heavy and bulky laptop bag, I just have a large purse that fits my iPad. Yes, I probably use the iPad more for consumption than productiviy, but in those moments when I can be productive on the iPad, it really is worth its price, and more.
But that's just me. Your experience will be different. Most of my colleagues feel they don't need a tablet, or they are waiting for something that fits their needs. (for example, one co-worker wants something the size of the iPad that opens multiple active windows at once) So if you don't have a need for an iPad, no need to get it. Save your money for something else you really need/want.