The wordpress team are really a bunch of smart and hardworking people. No longer than 2 days afeter they releaed the release candiidate 1 for worpress 2.3.1, they have now made an official release for a stable release of WordPress 2.3.1
Apparently, there was a major security issue with XSS with WordPress 2.3.
An XSS problem that can be exploited if your php setup has register_globals enabled. For this reason, upgrading to 2.3.1 is advised.