Actually it’s been out a couple of days now. At first blush (for maybe a couple of minutes), it looks pretty good. According to the various press releases it is faster than the previous version. Without actually timing anything my opinion is that statement appears to be true. As an aside, I’ve been seeing articles around the web suggesting it may be an IE killer on the Windows platform.
Installing it on a Mac requires some steps. Connect to http://www.mozilla.com to download it. Be sure to select the appropriate language. There are two versions of English available. There is English (American) and English (British), which is presumably for the rest of the world. The new version of Firefox needs to be installed by an administrator account. Then again, in my case it could be because that’s how I installed it the first time around. The file inside the DMG replaces the old Firefox.app file. As before it is a drag and drop installation.
There are a number of changes to the program itself. The average user probably won’t notice much. Essentially, the motivation to update to the new version comes from the ability to access the new web standards as well as the bug fixes and security.