A rc2 was released due to a security issue in the previous 2.0 files, kindly reported by Steffen Rösemann.
Everyone using any 2.0 build should update as soon as possible to not be subject to XSS attacks through blog comments on the blog admin page immediately! Sorry for this inconveniece
More here: http://blog.s9y.org/archives/259-Serend ... eased.html