Yep, already RC2. Due to a (potential) critical bug in the update routine for the 2.0 series. The update would fail if your db table prefix was not "jos_". This is no longer the case with RC2. RC2 also contains a few minor bugfixes and theme changes (just restructured some of the code).
To update from RC1 to RC2, the procedure is as usual. If you want to upgrade from 2.0 to 2.1, please read and follow this guide step by step
[ Download RC2 ] [ Update from RC1 to RC2 ]
