You got it wrong mate,
Here is the idea, very few percentage of people are looking directly for a certain products, those are the ones you can worry about. Someone looking for sony vaio cw... will probably go directly to amazon, and amazon ranks first for most of product keywords anyway
However, the major of people using search engines, are using it for semi-informational keywords. Reviews, Comparisons, Prices, and 90% of people who you are targeting are still looking for solution to their problems. This is why they are using google in the first place
And Amazon doesn't have those information, Affiliates do. So, as long as people have problems, Amazon and other affiliate shapes will be here. Actually, I believe it will just get better because more people are using internet, more affiliate options, more competition, the internet is maturing everyday, which means, more opportunities for us