The breadcrumb feature at this point only works in Admin pages and the wiki, and on wiki pages it only contains "Home" and the current page, so it's not very useful.
I suggest enhancing the page top of each section/feature something like what is shown below, to make it useful. If it is consistent across features, then site users will recognize its function. Of course, it would be optional.
Wiki:
Site Index > Wiki Home (if not the same as Site Index) > (Structure path if page is structure member) > Page (text, not link)
Articles:
Site Index > Article Home (if not the same as Site Index) > Article
Blogs:
Site Index > Blogs List (if not the same as Site Index) > Blog > Blog post
Forums:
Site Index > Forums List (if not the same as Site Index) > Forum > Forum post
Image Galleries:
Site Index > Galleries list (if not the same as Site Index) > Gallery > Image
File Galleries:
Site Index > File galleries list (if not the same as Site Index) > File gallery > File
Directory:
Site Index > Directory top (if not the same as Site Index) > Directory path
Etc.
Categories
How would/should the breadcrumbs work in conjunction with Categories (if Show Category Path feature is enabled?
Will it be confusing to have two breadcrumbs (or more, if the object belongs to multiple categories?