Netbook is cheaper; it isn't smaller and lighter than available laptops, but those get expensive when really small and light (under 2 lbs).

The tradeoff for cheaper price is less capability. If this is enough capability for your usage pattern -- and for many people, maybe most, it is enough for leisure use -- then the netbook is an excellent choice.

The capability is diminished in 2 areas:
1. apps that can run. Email and web browsing works well, after that it goes downhill fast. So check which apps matter to you and how well they do on the netbook.

2. hardware limitations. Smaller screen size and quality, keyboard, fonts, special devices. This is highly subjective. Some people are happy with 3 inch screen, others cant live with an 8 inch one. Ultimately this ties back to the first point (what apps you run).

My view is that netbook is a bigger PDA or phone and not a laptop alternative. Opinions vary (as I'm sure this thread will demonstrate soon).