Beta vs RC: What's new in the Windows 7 Release Ca...
Microsoft has attempted to make Windows much more customisable for the end-user. It has continued to add to the number of themes and other settings users have access to. Both Aero and simplified themes are available, and you have control over the opacity, colour and sound effects.
For those with a little more technical expertise, the RC will even let you change your Windows 7 login screen.
Beta vs RC: What's new in the Windows 7 Release Candidate?