WordPress 3.1.1 might not bring any new functionality to the popular content management tool, but it does fix a number of bugs and potential security issues.
These are the new changes the WordPress team announced on the official WordPress blog:
Some security hardening to media uploads
Performance improvements
Fixes for IIS6 support
Fixes for taxonomy and PATHINFO (/index.php/) permalinks
Fixes for various query and taxonomy edge cases that caused some plugin compatibility issues
WordPress 3.1 was released at the end of February and has already been downloaded nearly 4.5 million times.
Users that aren't experiencing any issues with WordPress 3.1 should still update because the latest version does address three security issues discovered by the WordPress security team.