You now have the option of a tablet too, such as the iPad or one of the Android alternatives like the Samsung Galaxytab. It's hard to say which would be better, but if you want to do a reasonable amount of typing then I suspect that a tablet with its on-screen keyboard isn't going to be as good as a netbook, but a large part of the laptop/netbook market has already moved or is moving to tablets.
The benefits of the netbook over a laptop are potentially longer battery life, and size. They manage this by having smaller screens, no DVD drive, and a less powerful processor. Of course there are disadvantages. The lower power means that the netbook can be pretty slow to boot and slow to run applications like Word. If you choose carefully you can find a keyboard that is just as good as a laptop, though again the size of the netbook necessarily means the keyboard will be a little cramped by comparison. It is possible to run a netbook on Linux, so that it boots and runs faster, but you need to be a reasonably tech savvy person to do that, I think. You also need to think about what you look at on the web. If you watch a lot of video then a netbook might not be powerful enough. If it's more static pages and reading stuff then there shouldn't be a performance issue.
Swings and roundabouts, and as ever, the true answer to your question is "It depends".