Beta vs RC: What's new in the Windows 7 Release Ca...
Microsoft's other taskbar innovation is the introduction of Jump Lists. Designed to replace right-click context menus in the taskbar and provide tighter integration with applications, Jump Lists were available in the Beta but have been refined in the Release Candidate and given slightly more polish. The Frequent list has also been tweaked so that it only shows the top 10 accessed files and folders.
Beta vs RC: What's new in the Windows 7 Release Candidate?