I've read many times that G is slowly devaluing internal repeated page links. IE, take an amazon.com type setup or a tackledirect.com as an example. However everything we're seeing in surveys continue to show customers are often most comfortable with the traditional categories so we're hesistant to go to a category structure that drills down. We'd rather do the drill down at the top of each category page, IE: Click on Brands--> Nike and you're taken to a Nike page with 5-10 subcats. Click on one of those and at the top of that page you can shop by price, color, size etc. I still find it confusing when all the categories vanish on the left hand side but it seems thats the direction G is pushing all of us?
What do you mean? Devaluing how? In what way? Why would you choose to build a navigation structure for Google? Build your navigation for users. Period.