Nobody had thought 2 years back that the netbooks would become so popular. Last year, the netbooks had already conquered 20% of the total notebook market. This year, it is being estimated that netbooks will account for nearly 37% of the total notebook sales by the end of this year and about 40% by the year 2012(!).
However, by 2012, I don’t think there would be any difference based on the feature set between a notebook and netbook (except for the small size, of course).