Robert_Charlton - 8:11 pm on Jan 25, 2013 (gmt 0)
Hi bbarbeau - You're right to think that faceted navigation can be "a duplicate content nightmare".
If the product pages are put into folders, and the product page urls reflect those folders and the different ways of reaching the pages, then you create the duplicate content. To avoid this, the new approach is not to put the products in folders, and avoid creating those multiple urls.
Take a look at this discussion, which I believe is the best we've had on this topic...
Choosing the best url structure
Two comments I made in the thread might help address the immediate inevitable questions you're going to have, and also address your breadcrumb question....
...It's important to understand that the navigation hierarchy and the folder hierarchy are independent of each other, though it's often supposed that they must be the same.
Regarding breadcrumbs with this arrangement, I suggest multiple breadcrumbs indicating most likely nav paths from home, and that they be placed toward the bottom of the page, where they give the visitor most useful navigation options.
It sounds like the situation you're describing has breadcrumbs tied into a folder/directory structure, which is fatal. IMO, you can't do it that way.
As realmaverick summarizes the way it's done in a well-known sample site we looked at (we generally don't discuss specific sites here publicly)...
actually keep their products at top level and use breadcrumbs to demonstrate the relationship of the file, within their website
You definitely should have a hierarchical navigation structure, but, again, that nav structure should be independent of the product page urls.
PS: Added clarification about product urls in second paragraph above.