This release candidate brings a couple of improvements, notably the ability to register a user from the Distribution Wizard and to auto-generate the main wiki descriptor at start up. The Chart Macro comes with new parameters and the UI for page rename/copy has better labels. On the technical side, this release brings the first, experimental, version of the minimalistic XWiki distribution.
Full release notes available at http://www.xwiki.org/xwiki/bin/view/ReleaseNotes/ReleaseNotesXWiki80RC1
See http://jira.xwiki.org/secure/IssueNavigator.jspa?reset=true&jqlQuery=category+in+%28%22Top+Level+Projects%22%29+and+fixVersion+in+%28%22%38.%30-rc-%31%22%29+and+resolution+in+%28%22Fixed%22%29 for more details