The Google Webmaster Central Blog announced more detailed warning are now being displayed to those using Google Sitemaps, when minor problem are spotted.
Previously, Google showed any problem, be it large or small, as an error. Now small issues that are “confusing or inaccurate” are considered “warnings” and large issues that make sitemaps unreadable are considered “errors.”
Here is a sample screen capture of an error/warning report:
We have more discussion and comments from Vanessa Fox at Sphinn.
In addition to this update, I reported at Search Engine Roundtable of a new Google Webmaster Link Tool July 2007 Update.