The beta phase is over, and the talented folks behind WordPress feel that 3.3 is ready for release. As with the standard process, the first release candidate is available. If no issues are reported with this release, this may very well be what we get for WordPress 3.3, so it’s time to put your testing hats on and hammer away, especially if you’re a plugin or theme developer.
If you run into any bugs, don’t forget to report them and contact the support forum if you need help.