You're a writer, and if you're thinking about buying an iPad, your primary concern is whether it will help your writing.
Can you write on it?
Image: iPad home screen
Yes, you can.
The big benefit is that the iPad just makes it easier to write wherever you are. I love the iPhone, but the dinky little keyboard is sheer hell. The iPad's keyboard, while still obviously not a full-size keyboard, is a pleasure to use: just watch the screen, and if you've made a typo, the iPad will usually auto-correct it as soon as you hit the spacebar.
After playing with it for a while, you'll be able to write on it almost as well as you do on your laptop.
Apple's Pages app, while not essential (there's the iPad's Notes app, and many other notepad apps) makes writing easier, and you don't need to confine yourself to simple text documents.
As you can see in the image below, Pages has 16 templates: you can create flyers, project proposals, recipes, and much more.
Pages documents look wonderful. Unfortunately however, there's no word count functionality, which ruins the experience for me. I like to know how many words I've written.
(If you know of an iPad word processing app which has a word counter, please tell me -- I've been searching, but haven't found anything yet.)
Writing on your iPad is fun; it's not like work at all.