There is a lot in Firefox 2 RC 3 that you can play around with and give us feedback on:
Visual Refresh: Firefox 2’s theme and user interface have been updated to improve usability without altering the familiarity of the browsing experience. For instance, toolbar buttons now glow when you hover over them. We will continue to improve the look and feel throughout the release candidate process.
Built-in phishing protection: Phishing Protection warns users when they encounter suspected Web forgeries, and offers to return the user to their home page. Phishing Protection is turned on by default, and works by checking sites against either a local or online list of known phishing sites. This list is automatically downloaded and regularly updated when the Phishing Protection feature is enabled.