Many improvements are included from the last stable release. This release is focused on bug fixes, usability improvements and rounding off the feature set.
Most important changes:
All tags are now automatically output, there's no need to manually select them from the settings page.
Output of the various title, description and URL tags has been standardized to default using the same values.
The meta tags have been given manually assigned form weights, to aid with grouping them logically based on their purpose.
Added the page title meta tag (deprecating the Page Title module), Standout, Syndication Source, Original Source and Logo tags.
URL tags (canonical URL, etc) how use the path alias by default.
API change - meta tags can now have multiple values by giving the "multiple" attribute the value TRUE. The dc.contribtor tag is the first to use this.
Default values are no longer automatically entered into edit forms, they are instead only assigned during output.
Initial support for importing data using the Migrate module.
A few more tasks still need to be done before 6.x-1.14 is released, along with additional testing.