Well, final until bug fix versions come out, such as Firefox 3.5.1, etc.
Mozilla FTP Link - Mac
As you can see, Firefox 3.5 final hasn't yet been released on the main Mozilla website, but it's been uploaded to the FTP servers so you can download it already. It will probably come out on its website later today.
Update: Firefox 3.5 is now available on it's official website.
Here is also a video with what's new in Firefox 3.5:
