Firefox 4 may be only a few weeks old, but believe it or not, Firefox 5 may released by the end of June. Users who want to gain access to the latest preview build can download a copy directly from Mozilla.
A list of features that may be expected include:
1.) Multi Tab Select. This will allow you to close a small group of tabs, or move a select few off the tab bar to create a new window.
2.) A Brand New Tab Page Layout.
3.) Add-ons will get standardized toolbar support.
4.) File Upload Indicator.
5.) The removal of a home button, in favor of a home tab.
6.) Built in PDF Viewer / MP3 Playback decoder.
7.) Taskbar Web apps. This will allow developers to include a drop down menu from the browser tab to allow for easier site navigation.
8.) Integrated Identity Management for easy website sign in.
9.) Social Sharing from the URL bar to Facebook, Twitter, and possibly others such as Reddit, and Digg.