UPDATE: Now the folder-enabled lists are supported.It was a webpart project originally but I created the delegate control version to modify all the libraries at once. Both versions can be found in the download section.
The OOTB SharePoint 2010 document library doesn't render a full path to the curent folder in page breadcrumb - it shows only the start end the end of the path:
The delegate control in the solution modifies a breadcrumb:
All the nodes are clickable. The idea (what is being replaced) is illustrated here:
Feel free to suggest improvements at email@example.com.