Want your breadcrumbs to show the tags your post is in, the latest development build of Breadcrumb NavXT will do that. To accommodate this new feature the settings API has been modified a bit to rename one option and three new ones were added. Naturally, hierarchical categories are the default setting, but if you’d rather use a flat scheme that can be done through tags. This is the only method to achieve displaying “multiple categories” that will be supported by Breadcrumb NavXT.
An additional note on the new breadcrumb class for 2.1. It will be possible to support breadcrumbs for pages that are dynamically generated by other plug-ins on existing WordPress pages. An example of such a page is the product pages created by e-commerce. This is due to a change in the class that has the breadcrumb generated separate of output. However, this does not mean I will be supporting these other plug-ins. The responsibility ultimately rests on the shoulders of the plug-in developers to support this. Note that the administrative interface will not work with this usage as the overriding plug-in will need to call and manipulate the class itself.
[end of transmission, stay tuned]