Ryan Boren today announced the release of WordPress 3.1.1. The release addresses over 30 maintenance and security fixes including performance improvements, increased security with media uploads and fixes for permalinks.
One of the fixes avoids a PHP crash in certain environments and another addresses an XSS flaw, therefore I encourage you all to update to this latest version when you can.
More information can be found about 3.1.1 at the link below :)
Link: WordPress 3.1.1