The uploader of the official WordPress theme directory has received a rather helpful upgrade courtesy of Otto . The previous version of the WordPress theme uploader checked the themes against the theme review guidelines , but only reported the first error that it encountered, sometimes trapping theme developers in a frustrating cycle of trial and error.  The new version performs an even more intensive scan of the theme and returns a list of all results, providing theme developers with a handy to-do list to get their themes up to spec for the directory.

The rest is here:
WordPress.org Theme Uploader Gets Smarter