Despite the healthy adoption rate by webmasters so far, implementing the rich snippets markup correctly can still be a major challenge. To help address this, we’ve added new error messages to the rich snippets testing tool [google.com] to help you better identify and fix any problems with the markup...
We are now adding support for a Breadcrumbs [google.com] markup format that allows webmasters to explicitly identify the breadcrumb hierarchy on their pages.
I still need to figure out what exactly they're saying, what's new, what's revised and what's old news. But it looks like Google wants to give more sites a shot at rich snippets and breadcrumbs in the SERPs. So the experiment must be testing well.
Fair news! It seems to me, that keywords in breadcrumbs are ranking the same way as keywords in url, or domain name. Adding keywords into "breadcrumbs" gives us possibility to influent not only to snippet's view, but also to the SERP' positions.